Keeping the rollers rolling in your roll grinding shop – partner with Grinding Techniques for perfect steel production

Steel manufacturing companies play a significant role within the South-African economy, not only by providing much needed jobs but also being responsible for the manufacturing of material to be used in various parts of the construction, mining and manufacturing industry.

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Grinding Techniques – a Tyrolit Swarovski Company, locally manufactures a variety of products under the brand name Andor for roll grinding used in the refurbishment of rolls in steel mills. From non-reinforced cut-off wheels used to cut steel samples prior to sanding with (NCH) No Centre Hole sanding discs, to cleaning of the surface in order for the metallurgy of the materials to be analyzed all the way to the roll grinding wheels in the grinding shops. Whether you need abrasives for laboratory work, or roll grinding shops, we offer a complete package to cater for all your abrasive requirements.

Due to the continuous use of rolls to their limit in the production line, an ever-high demand is placed in terms of wear resistance and surface structure of the rolls to promote increase in life and usability. Roll grinding shops within steel plants in particular require high quality grinding wheels to grind and prepare the rolls for use and re-use after refurbishment. Whether focusing on cold or hot mills, it is important to note that each mill presents their own challenge when it comes to machining rolls. Different rolls are used in the process from work rolls to back up rolls and these all have different profiles ranging from flat, CVC or Crown shaped. With new developments in the materials used for roll grinding such HSS, ICDP and forged steels various materials are now presented with a higher percentage chrome content for wear properties, and the advent of fully automated grinding machines, it is now of utmost importance to use reliable, consistent high-quality grinding wheels.

Hot mills require wheels offering fast stock removal rates and high performance, where surface finish tends to be less important. These rolls can range in diameters from 600mm to 800mm and with lengths ranging from 1600mm to 3400mm. In strip- and-plate mills, these diameters can go up to 915mm. Due to their extremely high stock removal rates, grit sizes ranging from 30 to 46 are normally preferred.

Cold mills on the other hand doesn’t have the same amount of material to be removed, but surface finish plays an important role. The work rolls in cold mills range in diameters from 300mm to 700mm and come with lengths up to 2500 mm. Grits sized between 46 and 150 will be preferred, as a finer grit is required to ensure a better surface finish.

Back up rolls in both hot and cold mills provide the necessary support and pressure to the work rolls and are larger in diameter going up to 1600mm. Usually made of cast and forged steels with a chromium composition of 2 to 5 percent, they are not ground as frequently as work rolls but have more material to be removed – in some cases material of up to 2 mm.

Common problems experienced in roll grinding shops such as grinding chatter, traverse marks and bruising can be eliminated when partnering with a manufacturer that understands the quality demands within the industry, and produce wheels of only the highest standards. Grinding Techniques’ research and development center regularly test and review products to ensure that grinding wheels produced conform and exceeds the required standards, and that optimum results, longevity and value are evident when using our products.

Since 1981, we have been a trusted precision wheel supplier to steel mills. Our years of expertise and the latest cutting-edge technology allow us to combine high quality grains and proven bonding systems to manufacture wheels with exceptional stock removal rates, cooler cuts and longevity.

Part of the Tyrolit group since 2014, we are also able to supply specialised Tyrolit grinding wheels specifically manufactured for wire rolling mills. As these mills make use of grooved tungsten carbide rolls, they have a diverse range of wheel designs with specific profiles. As these profiles get worn quite quickly, they need to be regularly ground. Metal bond is the wheel of choice due to its high-profile holding properties for this complex application. With the CSS Wire roll range of super abrasives made in either metal, resin bond or electroplated, you will get both longevity and high stock removal with quality that never disappoints.

Apart from manufacturing and supplying precision grinding wheels, we also carry a range of dressing wheels to dress the wheels back to its original profile, which can be tailor-made with regards to sizes used on different machines.

Grinding Techniques is able to offer a complete abrasive solution with products to suit various applications. With constant innovation, development and research, we have been the preferred precision partner for decades. Let us help you keep the rollers rolling. Contact our precision business development team for more information on customised specifications and sizes to suit your requirements.

For more information contact us: 011 271 6400 | info@grindtech.com | www.grindtech.com.

Getting the job done with Ceramic Abrasives

Ceramic abrasives are one of the newest innovations in grain technology. This high-performance grain has the ability to constantly re-sharpen as is wears, providing fast cutting action through its usable life. They provide the longest life and fastest cut rate of all coated abrasives. They represent the ultimate in performance, providing an aggressive, consistent cut under moderate to high pressure. Ceramic grains feature very small fracture planes which allow each grain to constantly re-sharpen and provide extremely consistent stock removal through its entire life cycle.

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Grinding Techniques proudly South African abrasive manufacturer and coated converter offers ceramic abrasive technology through our partnership with Starcke and Deerfos Abrasives. We offer a wide range of basic and finished products for almost every kind of application. At Grinding Techniques our aim is to provide you with the best coated or bonded abrasive product for your manufacturing process actively, objectively and reliably.

Typical applications where one would benefit from using Ceramic Abrasives includes but is not limited to:

    – Tough and hard to grind materials (Ceramic grains self-sharpening properties ensures a constant high material
    removal rate)
    – Heat and burn sensitive materials (The Top size cooling agent ensures a cooler cutting action eliminating heat
    buildup and premature dulling of the grains)
    – Applications where the output of parts in high volumes within the shortest time possible is a requirement. (Due
    to the fast cutting action of ceramic grains, the material removed is far superior to any other conventional
    abrasive grain in the same amount of time)

The quality of coated abrasives depends on numerous parameters such as the amount of grain and weight per unit area, the quantity of base, topcoat and curing temperatures. These parameters have been defined with a view to production and substantiated by quality assurance measures after every manufacturing step for each product. Not only do we manufacture abrasive products according to ISO standards, at Grinding Techniques we also strive to consistently meet and exceed maximum standards to ensure compliance with strict customer requirements.

Longevity and outstanding surface quality are the most important factors when it comes to supplying quality coated abrasive products. The world of “coated abrasives” presents itself with as much diversity as there are materials in order to achieve precise stock removal on metal, varnish, wood, natural stone, glass, plastics, ceramics and rubber. Our stock is easy to cut to all shapes, lengths and widths. Being a local converter of coated abrasive products, this is done according to customer requirements in order to facilitate and optimize delivery time, logistics and stock keeping for all parties concerned.

Coated abrasive products supplied by Grinding Techniques are designed to give the finishing touch to a wide variety of materials in the metal and wood industry and many more industrial sectors.

Contact us for the latest innovation in coated abrasives. Training and technical assistance is available from our product specialists who are ready to provide solutions to all your questions and processing issues.

Contact us on: 011 271 6400 | info@grindtech.com | www.grindtech.com.

The Art of Hand Sanding

Grinding Techniques explains how important it is to choose the correct sandpaper when doing some hand sanding.

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We all love the speed and convenience of power tools when refurbishing furniture or sanding the garage door at home. But once the heavy sanding is done, the power tools finish
finds it difficult to compete with a little hand sanding. Power sanders leave a small but noticeable scratch pattern that could become more visible after your final coating is applied.

Hand sanding even when using the same grit size that was used on your power sander produces a finer and more consistent scratch pattern which normally disappears under the
first coat of varnish, stain or oil. Hand sanding also gives you more flexibility and control when it comes to sanding in hard to reach places. When sanding contours, corners and
curves there is not much that beats a sheet or strip of sandpaper that can also be used with a sanding block.

When taking on a project at home or at the office, we can agree that anyone would like to do as little sanding as possible. Therefore, we only buy the correct amount of sandpaper and
variety of grit sizes that we think we might need to complete the project. In most instances you will be able to complete your project with just 3 grit sizes of sanding sheets, for example
100, 150 and 220 grit. It is always advised to test a small sample piece of wood on your project to see whether you will reach your desired finish before purchasing your sandpaper.
It is also recommended not to sand with half used sandpaper scraps due to their bluntness and inconsistent wear as it can leave uneven scratch patterns on your surface.

When sanding by hand we are left with two choices, wet or dry sanding. Dry sanding offers more control and you have good visibility of what you are doing and the finish. Dry sanding
however does tend to clog your sandpaper much quicker. It is always more beneficial to use a stearate coated sheet equipped with an anticlogging agent for such dry sanding applications.

In wet sanding, use a liquid such as mineral spirits or soapy water to provide lubrication that aids in floating away the debris that would have clogged the sandpaper. For this application,
use a silicon carbide wet or dry abrasive sheet, more commonly known as water paper.

Finally, you can use non-woven hand pads that contain just enough abrasive to remove small imperfections without cutting through your finish.

For more information contact us: 011 271 6400 | info@grindtech.com | www.grindtech.com.

Making Chips Count

Who would have thought that an abrasive grinding wheel can be used in the production of chips? This is particularly pertaining to chips made from corn. The history behind milling corn to maize goes back many centuries, where ordinary stones where used. One being stationary and the other stone on top being rotated by hand to grind or mill the corn into maize. As demand for maize products grew more and more, millhouses became very popular and the milling stones utilized grew in size, the principal stayed the same by having one stationary stone (bed stone) and the other one rotated (runner stone) driven by livestock, windmills or electrical motors.

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Producing chips from corn uses the same principle to grind or mill the corn to a finer powder. The famous tortilla style chips start with cooking the corn kernels in water with the addition of limestone to soften the husk from the corn. The cooked corn is then fed into a perforated rotating spinning drum to loosen the husk which is then washed away by using high water pressure, exposing the softer inside. Ready to be fed to the milling process, a screw is used, where it will be fed in between grinding stones to be milled. The millstones are used in pairs one being stationary called the “bed stone” and the other rotates called the “runner stone”, the rotating stone does the actual grinding or milling of the corn. These stones have a special design to it, and is made from fused aluminum oxide with grit sizes ranging from 46 – 120 depending on the required texture, in a vitrified bond. The special design relates to the concave inner part, which has deep grooves called the furrow coming up onto flat areas called lands, out to the outer edges where the actual grinding will take place with smaller grooves called feathering or cracking. The two stones are set to a specific thickness depending on the consistency required. As the corn is fed through the bed stone the inner grooves feed the corn to the outer side of the wheel with the smaller grooves, and as the runner wheel spins, the corn is then ground into Corn Massa (Spanish for dough). Now it is ready to go further down the production line to form the end product.

These types of stones are also used to grind, chocolate, coffee, cork, mustard, paint, snuff and sugar cane etc.

Grinding Techniques, a Tyrolit company and proudly South African manufacturer is a key supplier of ANDOR grinding wheels to the milling industry. We offer local manufactured products as well as imported Tyrolit wheels. Size, specification and configurations can be customized according to customer specific requirements.

Dedicated support personnel are ready and available to provide you with all the support and advise required to make your chips count!

For more information contact us: 011 271 6400 | info@grindtech.com | www.grindtech.com.

Grinding Techniques, Your Coated Partner for Brilliant Metal Surfaces

Industrial applications require a high degree of specialization. Grinding Techniques offers you Pearl grinding abrasive products from Starcke – the exact tool for your grinding needs.

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With these products a perfect surface and optimal product life can be assured. You can rely on Starcke Coated Abrasives as it carries the “Made in Germany” quality mark.

The Pearl grinding product range obtains its uniqueness from the mineral (grain) used to perform the cutting action. Granulated abrasive grains are pearl shaped that ensure consistent surface quality and removal rates. This abrasive technology is also known as agglomerate abrasives. Agglomerate abrasives is a combination of several identically sized abrasive grains that are shaped into a larger granulate using a resin before being spread onto a backing. Synthesized like this these abrasive granules form a firm bond that are attached to a material backing.

There are a few main advantages one can benefit from using the Pearl coated abrasive products. Very consistent surface finish is ensured; abrasive minerals go through a self-sharpening process throughout its life cycle, thus having continuous and uniform sharp edges exposed. Stock removal rates are higher than with conventional abrasive grains and longer longevity in the product life ensures perfect results whilst saving costs and time.

The Pearl range is well suited for the repair of coils and plates in a rolling mill. Pearl products also display their high performance in applications involving the use of water, emulsion and oil. With its high bond hardness, Pearl abrasives have the ideal application characteristics for edge grinding of flat rolled steel materials. Due to its uniform surface grinding characteristics they are perfect to produce a polished or matt surface finish.

Our Pearl offering is also suited for centerless grinding of tubes, bars and cylinders with a bonding system that is optimally suited for wet and dry grinding machine applications. With its regenerative concept, consisting of granulated abrasive grains and bonding system, the Pearl product offering guarantees a consistently uniform wire surface finish. This ensures perfect removal of mill scales from the wire and a uniform feed of the wire material throughout the product’s useful life, significantly reducing wear of the drawing plate.

Contact one of our Product Specialists at Grinding Techniques for a Pearl grinding solution to benefit from a product with longevity whilst maintaining a consistent stock removal and a consistent scratch depth and workpiece surface.

For more information contact us: 011 271 6400 | info@grindtech.com | www.grindtech.com.

Must have abrasives for your toolbox

Any DIY enthusiast will inevitably need to cut, grind or sand something. A selection of abrasives is a must have in your toolbox for any DIY project. The market offers an extensive variety of abrasive products to suit various applications ranging from sanding to cutting and grinding at home.

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A broad range of cutting-and-grinding discs suited to many applications are available in different sizes and specifications. As discs are manufactured for both ferrous and non-ferrous materials, care should be taken when choosing the correct disc for an intended application and the information displayed on the disc label should be taken into account.
Apart from conventional cutting-and-grinding discs, some manufacturers carry a special purpose cutting-and-grinding disc range suited for specialised applications like radius cutting or cut-and-grind applications.

Most cutting-and-grinding discs are available in different sizes to fit both the 115-and-230mm standard diameter angle grinders. When choosing a quality disc, look out for a brand that offers fast and smooth cuts with high stock removal, durability and longevity.

Discs, rolls and paper all form part of coated abrasives and are used in numerous different applications. Whether you are sanding by hand to smooth down a surface or using a powerful belt sander or right-angle grinder to remove large amounts of material or shape a piece of wood within seconds, there are various products available to get the job done quick and effortlessly.
When choosing the correct sanding paper, you need to evaluate the intended application first. Cabinet paper more commonly known as “Wood Sanding or Garnet Sheets” is known as a cost-effective product that provides a fast cutting action and uniform quality finish on woodworking applications, and is ideal for sanding wood surfaces treated with primer, sealer, lacquer, paint and other liquid coatings and finishes. Waterproof paper sheets more commonly known as “Wet or Dry or Water Paper Sheets on the other hand, offer a bit more longevity, faster cut rate and a consistent finish with popular applications like light duty metal sanding, defect removal from paint surfaces, sanding of composites and fiberglass, as well as filler sanding, sanding between sealers and coats of paint or varnish.

Floor sanding rolls or 300mm X 1m rolls, is an economical product with great versatility for a variety of general-purpose applications and offer a heavy-duty backing that ensures fast cutting action – ideal for hand sanding, paint and rust removal. Handy rolls more commonly known as “Economy or Emery rolls” come with a flexible cloth backed material best suited for scouring, deburring, breaking edges and the removal of rust and scale from metals. All available in various grit sizes and 25, 40 and 50mm widths to make the choice for your application easier.
Abrasive discs are another product considered as an essential abrasive for your toolbox. Velcro backed sanding discs or sheets are used with power sanders and allow for a 40% to 50% faster cut rate with a more consistent and uniform scratch pattern than other conventional abrasives. Typical applications would include sanding wood and paint removal. Fiber discs, also used on power sanders are used for high stock removal and require a suitable back up pad.

Flap discs are bolted directly onto a right-angle grinder offering both high stock removal and sanding applications. With flap discs available in different grit sizes and specifications, they have become a popular alternative to conventional resin Fiber discs.

Whatever abrasive product you choose for your toolbox, you are sure to find a vast selection of options at your nearest retailer.

Article courtesy of Grinding Techniques: 011 271 6400 | info@grindtech.com | www.grindtech.com.

Important safety factors to consider when choosing products for cutting and grinding with angle grinders

A right-angle grinder, commonly known as an angle grinder is a very powerful and useful tool but can also be a very dangerous tool if not used correctly.

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Selecting the correct size machine is essential to ensure a safe operation – for instance using a 230mm diameter machine to grind down welds on palisade fencing will prove to be very unmanageable and quite possibly very dangerous.

Conventional angle grinders come in various sizes ranging from 100mm up to 230mm diameter, with the 115mm and 230mm diameter as the most popular in South Africa.

When selecting the correct angle grinder, the size of the disc that will be used should be considered. A disc too large for the given machine (i.e. using a 125mm diameter disc on a 115mm diameter machine) will run at a higher speed than it is rated for, resulting in a very dangerous operation. Disc size diameters are clearly displayed on the labels for easy reference.
Further to selecting the correct sized disc, power and speed of the angle grinder also plays a significant role. POWER refers to the measurement of input or output wattage that the machine uses (depending on the manufacturer). Generally, the rule of thumb is that a higher power rating ensures a better performance of the abrasive product. When an abrasive disc is cutting or grinding, it is putting additional load on the machine. If the machine is under-powered, the extra strain may cause a reduction in motor speed, causing potential damage to the machine and underperformance of the disc. More often than not, an underperforming disc then results in more pressure being applied by the operator which then makes the disc perform even worse and also potentially causes disc breakages.

SPEED on the other hand, is clarified as the rate at which the disc will turn (measured in Metres per Second and stated as the RPM). The maximum operating speed of a standard cutting or grinding disc is 80 metres per second (peripheral speed). Depending on the size of the disc, this will then relate back to a higher or lower RPM rating; 80m/s on a 115mm disc equates to 13 300 RPM, while 80m/s on a 230mm disc equates to 6650 RPM. For this reason, it is imperative that an angle grinder must only be used with a disc size particularly made for that machine.
Another very important factor to consider would be the standard accessories. All angle grinders should have a safety guard that must be fitted to the machine at all times , a handle and a retainer nut for securing the disc. Retainer nuts are available in various types and they are for fitting the disc to the machine, including are some that don’t require a spanner to fasten and loosen. Regardless of which type, make sure that you are not over tightening it as these machines are designed to self-tighten on start-up, therefore requiring only tightening by hand.
Remember to inspect discs for potential damage prior to use. The periphery of the disc should be intact, not chipped or frayed and it should be flat, not warped. Never attempt to bend or twist the disc as the fibre reinforcing will be damaged and potentially form a dangerous crack.

Safe usage and operation pictograms are displayed on each disc label that should present the following markings:

    OSA – Organisation for Safety of Abrasives: These manufacturers commit to certified quality management with documented processes and internal testing facilities of the highest competence ensuring product safety for the end user

    EN Standard – European safety requirement for bonded abrasive products (such as cutting and grinding discs – EN 12413)

    Safety pictograms – these pictograms show the required PPE to ensure safety for the operator and includes gloves, ear protection, eye protection etc.

    Material Applications – the disc will identify which type of materials it may be used on. Note that this will quite possibly only be a general identifier (such as “Metal”). Contact the manufacturer should you require more detail on specific applications.

    Wheel type – this will tell you whether the disc is manufactured for free hand cutting, stationary machine cutting or grinding applications.

    A cutting disc should never be used to grind with or cut anything but in a straight line. Bending the disc to cut a curve or radius will result in the fibre reinforcing becoming damaged and may cause wheel failure.

    For grinding applications, a minimum grinding angle of 30 degrees is essential. This is what is termed the angle of attack. The optimal range is between 30 and 40 degrees to the surface. Should you increase the angle of attack, the disc will be dressed more and the effectiveness of the grind will be reduced. This could also lead to chatter marks and large, deep scratches in the workpiece. Should you reduce the angle of attack, you run the risk of overheating the face of the disc which will cause the disc to start fragmenting and may become a major safety hazard.

    Taking the time to choose the correct tool and using this in conjunction with the highest quality, value for money abrasive products will ensure that you complete your task safely and with minimal effort.

For more information, please contact: 011 271 6400 | info@grindtech.com | www.grindtech.com.

Grinding Techniques Your Partner in Ship Building and Repairs

A wide variety of abrasives coated and bonded are used when building and repairing marine vessels. Grinding Techniques, a local manufacturer of bonded, and converter of coated abrasives is your perfect partner with quality abrasive products suited to various applications for the ship building and repair industry. The first thing that comes to mind when one thinks of large marine vessels being built and repaired would be enormous structures fabricated from very large pieces of metal.

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There are however thousands of parts inside a ship that also need to be fabricated and maintained by using a wide variety of bonded and coated abrasives. Cutting and grinding discs form a big part of the selected abrasive product range whilst fabricating these smaller parts which will include the vessels tubes, pipes, stairs and even the balustrades to mention a few.

Grinding Techniques locally manufactures a comprehensive range of Superflex cutting and grinding discs for all applications and materials to be cut or ground. Further to this, we also carry a full range of coated abrasive products for the finishing and polishing requirements of these manufactured parts.

When it comes to cutting and grinding applications on a vessel there would be a variety of scenarios to be considered, for example the accessibility of the area where the work needs to be performed and what material type is to be cut or ground. Understanding the final required finish of the material to be worked on is also of utmost importance when selecting the best suited abrasive product for the job at hand. Angle grinders would be the most preferred power tool to use in confined spaces of a vessel due to their size and the comfort of use they offer to the operator. Carbon steel, aluminum and stainless steel would be the most common material used for components in ship building. Special care needs to be taken when selecting the ideal cutting or grinding disc for each material type and application. Always ensure that the correct specification cutting or grinding disc is used for the type of material to be worked on. One of the common challenges in shipbuilding with various materials involved is the cross-contamination of cutting and grinding discs and material ground. Products specifically designed to cut aluminum for example should not be used to cut steel and stainless steel. When cutting stainless steel for example always use the disc on stainless steel only for its entire life cycle to preserve optimal product performance and avoid cross-contamination of materials. At Grinding Techniques, we have a full range of application specific “Superflex” cutting and grinding discs for every material to be cut or ground. Contact one of our product specialists for a safe and task specific abrasive solution for your applications.

Our full range of coated abrasive products include flap discs, resin bonded fiber discs and Velcro backed sanding discs to name a few – all manufactured with the highest materials to meet any surface finish requirement. In addition to this, we also offer a full range of wire brushes used in the ship building and repair industry.

At Grinding Techniques, the safety of our customers is a top priority. Operator training is offered to reduce the labor time spent while cutting and grinding as products perform at their best when used at the correct angle, pressure and speeds on the correct materials.

When tolerance is key it is vital to choose the correct partner for your precision grinding operations

The precision industry requires parts to have tighter tolerances and attain a specific surface finish whilst maintaining a low production input cost per unit, a challenging factor for many when wanting to maintain a competitive edge in the market.

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To achieve optimum performance, one needs to consider the complete grinding process. Correct coolant supply to the grinding wheel and workpiece is of utmost importance, machine spindle bearings must be in good condition to ensure vibration free grinding and sharp enough diamond dressers to open and not close the grinding wheel face are but a few factors that influence the overall process, vital to achieve optimal grinding results.

By choosing a partner that not only understands the importance of this but are in a position to provide technical know-how with the ability to locally produce products that meet these requirements, you can give your business the competitive edge with increased production output.

“We understand that using a grinding wheel is one of the most versatile and cost-effective methods to remove material from machined parts. A cutting action of hard and sharp abrasive grain particles from a rotating grinding wheel achieves this when the grinding wheel forces abrasive grains into the surface of the workpiece,” says a spokesperson for Grinding Techniques.

“An abrasive grinding wheel is a replaceable consumable that carries an abrasive compound on its periphery. They are manufactured of small, sharp and very hard natural or synthetic abrasive minerals, bonded together in a matrix to form the wheel. The grinding of precision components is only made possible by choosing the correct grinding wheel specification which is crucial for the achievement of high precision stock removal and or surface finish to very high tolerances. Due to the great number of variables involved, the grinding process is one of the most complex tooling processes.”

“With the advent of more exotic materials being ground, ranging from hard to grind metal sprays to tougher and harder tool steels, choosing the correct grinding wheel specification is becoming increasingly difficult.”

“Grinding Techniques make use of the latest technology in the ANDOR and TYROLIT range by using various high-quality minerals and proven bonding systems. This ensures a faster stock removal rate due to the self-sharpening effect of the grain and the properties of the bonding system that keep the grain in place for optimum performance. This combination is perfect to produce parts were tight tolerance and adequate surface finish is a prerequisite.”

“As a trusted precision partner, being the largest local manufacturer of precision grinding wheels in Sub-Saharan Africa, we at Grinding Techniques are able to engineer specific products for individual requirements with very competitive manufacturing lead times. Our comprehensive after sales service with technical expertise from our business development team and sales force ensure that we are with you every step of the way and ready to assist with any enquiries around the most optimum grinding process.”

For more information, please contact: 011 271 6400 | info@grindtech.com | www.grindtech.com.

Making the correct tool choice

In the modern age of industrial innovation, it has become more important than ever to analyse the performance of every tool at your disposal. The margin between success and failure, profit or loss may be determined by the small differences in production times and costs we often take for granted. More often than not we do things the same way we have always done them, even though the parameters and environment we operate in have changed.

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Why spend four hours battling to get a job ground and ready for shipping when one hour will do? Why employ three fettlers, occupy additional machines, PPE, electricity and other associated costs when the right tool could assist one fettler to be up to three or even four times more efficient? Why wait another day to invoice a job that could have been delivered today?

Today a wider range of alloys are being cast than ever before. Some alloys are lighter, and or harder, more abrasion-and-impact resistant, while others tend to react better to sub-zero temperatures or prove more heat sensitive than ever before. These alloys have been developed because the world we live in demands it. Seldom do we stop and put some thought into the machining, grinding and finishing of the said alloys until that moment of truth arrives. Panic stations! Luckily, our abrasive technology has developed at equally rapid rates. Manufacturing methods, bonding systems and mineral types have been evolving to keep up with the demands created by new modern innovative alloy introductions. At Grinding Techniques – a Tyrolit company, we are at the cutting edge of development and able to provide a solution for your abrasive requirements.

When one looks at the new range of ‘super alloys’ being developed, it has become increasingly evident that machining of these materials will be and is already a serious challenge. Grinding has proven to be one of, if not the preferred method, of shaping these alloys. Abrasive manufacturers all over the world are gearing towards the grinding, shaping and machining of these alloys with a far greater success rate over that of the machine tool bit manufacturers. New innovative products being developed have brought grinding and machining times of certain components down from 4 to 6 hours per part, to less than 24 minutes per part.

The Superflex Ceramic range of grinding tools are developed for rapid and accurate cool grinding on specialised alloy castings in excess of 700HBR. The results achieved when compared to conventional abrasive tools were almost incomparable. Grinding times on these hard materials were reduced by more than 66%, and as a result of the shortened grinding times we were able to lessen the heat being generated through friction by significant proportions with a noticeable cost saving as a result. Scrap rates as a direct result of heat cracks are now something of the past.

The ceramic range as good as it is for chrome and abrasion resistant materials does not provide the same performance level on cast iron, SG iron, manganese and steel foundries. Due to the fact that the grinding mineral offers a sharper, more aggressive grind on contact, but the bonding system employed breaks down in a different manner to that of conventional grinding wheels developed for softer materials. Selecting the incorrect tool – reduces the efficiency of the grinding tool on application and increases the cost to a point where it is just not viable to use.

So where does one begin when choosing the most appropriate tool for the job at hand? It starts by challenging yourself to achieve a more desirable result and produce a better end product, at a satisfactory cost level for the specific application.

You need to ask yourself what would you like to achieve? Faster grinding times with less of a bottleneck in your fettling bay? Lower grinding cost per component? Reduction in machine cost, or replacement cost? Better aesthetic finishing? All of them or at least a combination of the above are possible by selecting the correct abrasive type.

Grinding Techniques, a Tyrolit company, offers a comprehensive range of abrasives geared towards achieving your required optimum result. With more than 100 years of manufacturing experience behind us, we more than willing to conduct trials, assist with application optimisation, and work along-side you to tailor make a solution that attains your required results. Our comprehensive product offering uniquely qualifies us to assist in optimising your foundry requirements and making the correct tool choice.

Keeping the wheels of the transport industry rolling

Since the dawn of commerce and industry in the times when people were bartering for goods and services, it was just as important to produce the product as it was to be able to transport the product to the target market.

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Today the need for transport is far greater than before. The number of goods traded are infinite, and the competition to get your goods delivered at a competitive rate is a reality of business today. Goods are being transported all over the world, by ship, rail, road and air. Not only is the cost of delivering the goods important, but the delivery timeframe is just as important. Today, the best product in the world means nothing if it arrives at a cost that nullifies the performance of the product or if it arrives late.

South Africa relies heavily on the transport of goods from our coastal ports to our inland cities, and the supply and distribution of mined mineral to the point of either distribution abroad or beneficiation. Our infrastructure is the most advanced in Africa, and still growing by the day. Imports and exports are a critical function in most businesses today.

The logistics industry is one of, if not the fastest evolving sectors in Africa. For this reason, companies who manufacture the supporting equipment have become more competitive. Every tool is analysed for efficiency and cost-effective performance. Comparisons are being run between old and new technology.

To be part of every aspect of the transport value chain is a unique privilege. From the construct of new containers, building of overhead cranes in the container handling terminal, the airport handling equipment, the trailer that transports the goods from a to z, be it by truck or train, to the manufacture of the train rails, we offer products that provide solutions to almost every application.

Aluminium fabrication has become a bigger part of our day to day lives and even more so in the transport industry. Lighter, stronger designs are being put to good use. Aluminium has for long been a difficult fabrication material due to its low weldability and susceptibility for contamination. Grinding Techniques has developed specialised products for the effective fabrication of this material. The Superflex range of non-ferrous cutting and grinding discs, is complemented by the new non-ferrous premium flap disc range. Any professional fabricator knows that the tools
you choose not only makes your primary job successful, but the secondary applications to follow as well. If a regular steel or stainless-steel product were to be used to prepare a piece of aluminium for a weld, the oxidation that takes place on the surface during the preparation would require a secondary process of decontamination using acetone or other chemicals before a successful aesthetically pleasing weld would be possible. By using the correct abrasive tool, a perfect weld can be achieved directly after the cut or grind saving many man hours and making the job at hand much more cost effective.

We offer optimisation service without equal. The professional and scientific manner in which the performance of products can be compared is unrivalled in the industry, and the results speak for themselves. In an industry where “time is money”, this approach could be the differentiating factor between profit and loss.

We keep the Paper and Pulp Industry Rolling

The grinding of rolls for the paper mill industry is known to be one of the most difficult grinding operations. These rolls are normally very long relative to outside diameter, hard in composition and have very tight tolerances and surface finish requirements to be met.

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In most cases the grinding of paper mill rolls is a very time-consuming operation when it comes to both the roughing and finishing cycle of the process. Excellent operator skill and special attention to the grinding machine and its surroundings are also crucial factors when it comes to delivering a good and consistent result. Some of the common challenges faced in the grinding process might include, roll deflection and sag, vibration, wheel glazing, chatter marks, traverse marks and stainless-steel loading. The finishing process is commonly the most difficult and time consuming as some rolls might take much longer than others to grind.

Choosing the correct grinding wheel for the roughing and finishing cycles of the grinding process is of utmost importance. Using a too hard or too soft wheel or even a wheel with the incorrect mineral and bond combination could lead to the loss of a lot of time during the grinding process. Grinding Techniques – a Tyrolit Company – is able to provide the Paper and Pulp Industry with local research and development capability as well as both locally manufactured Andor wheels, and imported Tyrolit wheels. Both the Andor and Tyrolit grinding wheels are specifically formulated and manufactured with the characteristics for successful roughing and finishing cycles in the grinding process.

Grinding wheels consist of abrasive grains held together by a resin bond. The abrasive normally used is black or green silicon carbide, which is a hard and sharp mineral and suited for most rolls used in the paper mill industry. In the grinding process the grains’ sharp edges cut away the material and become dull (loses its sharpness) under the heat and pressure of the grinding process. The bond releases the dull grain from the wheel at the perfect time, exposing a new sharp edge of the grain, ensuring that these sharp edges are exposed for the full duration of the
grinding wheel’s life cycle. Using the correct grinding wheel will ensure that more material is removed per pass with minimal tendency of glazing and the least amount of dressing required.

Using two different wheels for the roughing and the finishing cycles when grinding paper mill rolls, have proven the most successful in the shortest time. For example, a grinding wheel used in the roughing cycle will generally be much too hard to be able to adhere to the required finish in the finishing process.

The objective of the roughing wheel is to remove stock (material off the roll). Grinding Techniques takes the following aspects into consideration when specifying a rough grinding wheel suited for the Paper mill Industry. The wheel needs to remove high volumes of material per pass whilst not having a tendency to burn the roll. The ideal wheel should also possess a free cutting action with minimum heat generated with the least dressing cycles required. A very consistent and uniform surface finish is also a top priority.

The finishing cycle of the grinding process has different characteristics compared to the roughing cycle. Considering the lower pressures and different speed and feed rates of the finishing cycle, the wheel matrix has to be adjusted accordingly. Lower grinding pressures could cause a wheel’s grains to dull and burn to the workpiece and chatter is often the result. The finishing cycle on roll grinding would require a finer grit wheel with a softer bonding system to release the dulled grains at lower pressures.

Contact Grinding Techniques, the largest local producer of resin and vitrified abrasive products for a tailored solution to all your grinding processes of various paper mill rolls.

For more information, please contact: 011 271 6400 | info@grindtech.com | www.grindtech.com.

Moving the automotive industry forward

Global earth warming plays a major role on climate change, in some parts of the world wreaking havoc with uncontrollable veld fires, severe flooding and drought. The major contributing factor being high levels of carbon dioxide that is released in the atmosphere by gas emissions from internal combustion engines. A renewed focus on climate change and stricter policies are changing the way in how motor vehicles will be produced in future. Manufacturers are downsizing engine size, but increasing engine capacity by adding turbochargers – placing huge emphasis on the quality and surface finish requirements of engine components. The reduction in weight of alloys and material chosen poses a great challenge in the machining of these components.

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Grinding Techniques – a Tyrolit company, has the experience and expertise locally in providing cost effective grinding solutions to cater for the OEM automotive component and automotive reconditioning market, especially the grinding of crankshafts. Our local R & D facility enables us to provide the best possible product specification whilst obtaining low machining costs per unit.

When considering the overall grinding process, Business Development specialists are able to offer support on all technical issues taking into account the preferred grinding solution, machine, grinding wheel and dressing tool. One of the major challenges experienced in Crankshaft grinding is wheels being “out of balance” and this is particularly due to lack of training on the correct safety checks, mounting and balancing procedures, as well as crankshaft wheels having bigger outside diameters and smaller widths, which accentuates any “out of balance” conditions. With proper training of operators this problem could be eliminated. Grinding Techniques is able to provide the necessary training.

With our local range of ANDOR grinding wheels, we are able to produce wheels of up to 1015mm in diameter.

The change to lightweight alloys and higher surface finish requirements on engine components has established a dynamic shift on the production of grinding wheels in both conventional and super abrasives. By using the latest technology in high quality Aluminum Oxide, CBN grain and bonding systems challenges experienced with issues relating to parts being ground out of round, and to non-sufficient tolerances, are minimised and further employed to the automotive reconditioning market, earthmoving equipment and armor-plated vehicles.

Specific to the automotive reconditioning market, we have products available to suit crank-and-camshaft grinding, polishing, valve seat and stem end grinding as well as the brake and clutch industry to name but a few. We also employ the latest CNC machining which enables us to produce wheels for the gear industry with a range of modules, pressure angles and starts required for continuous generating and profile gear grinding. With the addition of Sintered Aluminum Oxide in various products, we are able to cut down on the overall production cost per unit, whilst
still attaining a cool cut and good form holding on the grinding wheel.

Partnering with Grinding Techniques offering tailor-made products with competitive lead times and custom grinding solutions will go a long way in moving the automotive industry forward.

For more information, please contact: 011 271 6400 | info@grindtech.com | www.grindtech.com.

Playing an essential part in the Mining Industry

The mining sector plays a prominent role in the South African economy. With the increased demand for raw materials such as Manganese, Chrome, Nickel, Platinum and Coal from various consumers in a global economy, the need to mine cheaper, faster and more productive has never been more prevalent.

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Underground mining relies heavily on the ability to remove ground water from areas where shafts could potentially flood. Pump manufacturers are using harder alloy pump components that increase life span and reduces pump replacement cycles and down times. Better slurry pump designs and better metallurgical developments have all lead to significant reductions in operating costs.

Crusher Mills and pulverising mills are re-lined with harder, tougher liners to ensure better productivity and less down time. If one takes into account that it takes almost a full day to re-line a mill, and the average mill crushes several thousand tons of material per day, one can quickly deduce that a mining operation potentially loses millions of Rands in lost production for every re-line that needs to be done.

Fabricating the dragline buckets used in opencast mining presents various challenges. First the large metal plates made from specialised materials such as Hardox, or other wear and impact resistant alloy steels, weighing several tons needs to be unloaded. Then the plates are cut to shape and size using flame cutters or profile cutters. These parts now need to be bent, and before all of these pieces are welded together, the surfaces need to be prepared. This prep involves grinding the weld angles onto the plate and preparing the landing. Once the first root weld has been made, the procedure may call for a back-grind with a series of filler welds to follow as soon as this has been completed. These are constantly tested and checked for defects. If defects are found, a portion of the weld needs to be gouged out or ground out. The process continues until the weld is finally capped off.

The big earthmoving equipment trucks that work in conjunction with these drag-liners in moving the earth from point of mining to point of processing, have buckets manufactured in a similar fashion. The same can be mentioned about the side tipper hopper wagons manufactured for the rail industry and the side tippers manufactured for the road transporting sections. All of these components undergo a rigorous fabrication process.

Whether we are looking at the process of dragline open cast mining, sinking shafts for taking minerals from the earth, transporting raw material to the processing plants and smelters, or beneficiation processes – fabrication is in some form or another involved.

Grinding Techniques developed several Superflex products suited to these specific applications over the years.

  • The 230×7, 2×22, 2 AS30T Heavy Duty disc is unrivalled in stock removal and service life and perfect for grinding Hardox and alloy steels, as well as several other abrasion and impact resistant metals.
  • Whilst the 230×5, 2×22, 2 AS30T Back-Grinder and the 230×4,1×22,2 AS30T Pipe-Liner are ideally suited to the back-grinding operation where one merely wants to open the weld up without grinding away more filler material than is necessary.

Superflex also caters for the harder “super-alloy” materials now used in some of the pump casings and mill liners.

  • The 230×7, 2×22, 2 CA24Q Premium Ceramic and 230×7,2×22,2 ZA24R Premium Zircon wheels offer excellent stock removal and service life while ensuring a reduction in surface heat temperature when grinding sensitive materials.
  • For the thicker more demanding plates, we offer specially configured cup stones that produce high stock removal and longevity. Various specifications are available in 150/120x50xM14 or 5/8 and 125/100x50xM14 or 5/8, all ideal for big contact areas where a lot of material needs to be removed.

In assisting the Fabricator to finish their product more aesthetically, Grinding Techniques offers a full range of Tungsten Carbide Burrs, Flap Discs, Fibre Discs and Velcro Discs that provide for smoother surfaces prior to painting, and to repair paint and body blemishes along the way.

Apart from the above, we also have a range of diamond wheels and cutting discs for masonry and steel suited to the
various applications when producing wire and wire rope.

For more information on solutions and products customised for the Mining Industry, please contact: 011 271 6400 | info@grindtech.com | www.grindtech.com.

We help keeping the lights on

We have all heard of the trials and tribulations our National Electricity Provider face when it comes to conducting day to day maintenance. Often, planned and unplanned maintenance outages are scheduled to support the country ensuring electricity availability as far as possible. Not many of us know the kind of work required behind the scenes to keep the lights on. At Grinding Techniques, we are fortunate to be a partner to the electricity industry. Very involved in their work, we can share a little insight into the cutting and grinding processes they go through when dealing with a maintenance outage.

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One of the most common unplanned outages is referred to as a tube-leak. When a tube has an imperfection, or has worn so thin that pressure generated by the steam within causes a blow-out or explosion within the boiler, serious loss in efficiency is caused.

Working on boilers and steam systems come with its own challenges. When having to work at a height of 50m above the ground in a space no bigger than a bathroom cupboard with the task of cutting a piece of pipe 6m in length with a 9-inch angle grinder and virtually nothing supporting the pipe on either end, one can only imagine the complexity of such a task.

The vibrating piece of pipe from lack of clamping coupled with such a small working area providing only limited air circulation and low artificial lighting with the constraints of your protective gear providing but a lifeline at 50m above ground, poses the unplanned and unthinkable when having to race against a deadline of three to five days and dealing with failure of equipment that needs replacement.

Unsupported workpieces being cut in constrained space, at almost impossible angles, with arguably one of the most dangerous power-tools available to man, is a recipe for disaster if the artisan is not trained properly. We often criticize, but rarely understand the level of commitment, skill and patience these artisans possess. Much credit needs to go to these training schools where trainers spend hundreds of hours preparing artisans for the job at hand. They build simulators and conduct numerous tests, spend hours on theory and practical examinations. No effort is spared in the quest to prepare them for the challenges they are certain to face on the line.

These dedicated pipe fitters, welders and boilermakers are unsung heroes in a world forgotten in the electronic era.

It has been a privilege for Grinding Techniques to develop custom products for these hard-working people during the past decades. Our products provide easier, smoother cuts that are safer than ever before providing increased cuts per wheel to save thousands of Rands and man hours in the job at hand. As a result, less down time in tool changes amounts to a tremendous increase in productivity. A smoother cut in an environment where the job cannot be supported makes the operation safer, as there is a smaller likelihood of the wheel being gripped by the job ending in wheel failure – this and other big bore applications brought forth the development of the renowned Superflex 230×2, 5×22, 2 XR cutting disc.

A further development was the Superflex IPDS product range that successfully removes build-up in seconds. Once the pipe has been cut, mineral build-up on the inside of the tube needs to be removed. Our IPDS product removes this build up in seconds rather than minutes -adding to increased productivity on the line. Having proven themselves on this application, our IPDS points are available in more than one shape and size, to facilitate the different pipe sizes.

Grinding Techniques also introduced new innovative technology in cutting big-bore pipes with the latest abrasive product designs. Resulting in not only reducing cutting time significantly but also minimising the preparation time required prior to welding by several hours – all due to a reduction in change of the molecular structure of the material as we limit heat input during the cutting process.

The first “free-hand” 350mm cut off wheel was designed with these applications in mind. The Superflex 350x4x25, 4 ZA24P wheels work with an incredible rate of cut, and come with a very high safety rating. The machines used with this wheel have been available in other parts of the world for quite some time, but we have only been introduced to them fairly recently in South Africa. We believe that introduction of these machine will be seen more and more in the near future.

By introducing all of these innovations we as Grinding Techniques believe our contributions to a better productivity environment assist in the reduction of operator fatigue and improve concentration levels. Which in turn will assist all the key players in the electricity industry to keep the lights on.

For more information, please contact: 011 271 6400 | info@grindtech.com | www.grindtech.com.