top of page

our raw materials


Abrasive grain and bonding material are the basic elements of all our products.Schleifkorn und Bindungsmaterial sind die Ausgangsstoffe für alle unsere Produkte. Our main focus is on the high quality and reliability of these materials. We do not obtain any abrasive materials from Far East as we put our trust in our European suppliers. We do not compromise on our vitrified and resinoid bonds: All bonds are developed in our laboratory and tested in our test department.


Regular aluminium oxide


Particularly tough grain with low tendency to chip fractures blocky. Regular aluminium oxide has a long lifespan, however cool grinding is not possible.Regular aluminium oxide is used mainly for roughing, cleaning and deburring unhardened and hardened-and-tempered steels, forging grade steel, ingot steel and soft iron, steel, grey cast iron and malleable cast iron for manual and machine grinding. Modern grinding wheels in various grain combinations are also used.


Semi-friable aluminium oxide

Semi-friable aluminium oxide does not have the toughness and compressive strength of regular aluminium oxide, but chips more pointed. It is suitable for a wide range of applications that extend from rough grinding through to precision grinding.


Special fused aluminium oxide white, pink, ruby

Of all grain types, special fused aluminium oxide has the highest tendency to chip. White special fused aluminium oxide is particularly suitable for hardened steels and therefore used mainly for precision grinding. The fracturing characteristics of special fused aluminium oxide can be influenced by the addition of titanium or chrome oxide in various percentage amounts, i.e. it becomes tougher. White, pink and ruby special fused aluminium oxide can be used for almost all materials.


Monocrystalline aluminium oxide

Monocrystalline aluminium oxide is obtained by a different fusion process. The chipping behaviour of the monocrystalline aluminium oxide is similar to that of dark silicon carbide. Monocrystalline aluminium oxide has firm cutting edges and high compressive strength. The most important applications are the grinding of high-alloyed steels and grinding operations with high geometrical and dimensional accuracy. It is also often used in combination with other abrasive grain types.


Sintered aluminium oxide

Sintered aluminium oxide has a property that is not common to other grain types: It does not become blunt! Depending on the external load on the grinding wheel, various sized grain particles chip off in use, immediately exposing sharp-cutting tips. When the dressing infeed is reduced to that for conventional grinding wheels, sintered aluminium oxide produces optimal grinding results, and low peak-to-valley roughness does not pose a problem. The lifespan of a sintered aluminium oxide grinding wheel can be much longer than that of other conventional wheels (special fused aluminium oxide, silicon carbide), but it costs only about 1.5 to 3 times more. It can even be used on extremely hard tool steels and all high-speed steel types with astounding results. However, the performance of CBN is unattainable. Economic substitution of CBN is possible in many cases for individual components or small piece numbers.


Silicon carbide

Compared to corundum, silicon carbide is harder, but not as tough. It is therefore suitable for grinding the following materials:

• All types of glass, ceramic, stone, partly also engineering ceramics
• Aluminium, copper, bronze, brass
• High-alloyed, hardened steels (tool steels), nitrided steels
• Malleable cast iron and cast steel
• Hard metals in a sintered and hardened state



Light green silicon carbide

This abrasive is extremely aggressive and due to its special chipping characteristic, which can be described as "sharp edged and pointed", is used where material hardness and/or elongation are typical characteristics. With respect to the hardness, light green silicon carbide is still regarded as the best substitute for diamond for cost-efficiency reasons.


Dark silicon carbide

This abrasive is extremely hard, but much less brittle than the "green version". It chips blocky, comparable with regular aluminium oxide, whereby in comparison to the latter, sharp edges are produced. This gives dark silicon carbide its typical properties. 



Apart from the abrasive grain, the bond is one of the most important elements of a grinding tool. The bond holds the abrasive grains together in a very special way, which influences and controls the grinding properties to a large extent. Very dense, but also very open structures with numerous pores can be produced.

Modern vitrified low-firing bonds play an important role. They are produced synthetically in the majority of cases and reach their hardness and strength already at oven temperatures of up to about 950°C. They were developed specifically for the vitrified bonding of diamond, CBN and sintered aluminium oxide. At higher firing temperatures, these abrasives would be destroyed (oxidised) or – in the case of sintered aluminium oxide – fused to lumps, having virtually no ability to chip.

All bonds used by BSW have been developed in-house and are not available from any other manufacturers.

bottom of page