Norton 38A White Aluminium Oxide Straight & Tapered Cup Grinding Wheels For Precision Grinding

A grinding wheel is a precision tool with thousands of cutting points. It consists of abrasive grains held in a matrix of bond and separated by pores. The abrasive grains are the cutting points while the purpose of the bond is to hold the individual grains together.

The pores (hollow spaces between adjacent abrasive grains and the bond) serve to provide clearance for coolant penetration and metal chips removed in the grinding process.

When the wheel is rotated at grinding speed and applied to the workpiece, the abrasive grains cut the material that is being ground, removing the material in small chips.

Under the action of the forces imposed during grinding, the abrasive cutting points are worn flat, resulting in the points becoming blunt. This causes an increase in friction, and a build-up of heat.

The increase in grinding forces causes either the abrasive to fracture, exposing new cutting edges, or fractures the bond bridges holding the abrasive grains. In the latter case fresh abrasive grains are exposed to cut the workpiece.

In normal vitrified grinding applications, the wheel has to be dressed. By varying the properties of the abrasive, the type of bond, the make-up of the wheel, it is possible to produce grinding wheels with a vast range of different grinding characteristics.

Traditional straight grinding wheels are used to grind with just the outer circumference of the wheel. The face of a cup wheel provides an additional radial grinding surface, which can be beneficial in some applications.

These are available in two forms; shape 06, where the two sides of a straight cup wheel are at a right angle to the base. With shape 11 tapered cup wheels the sides taper outwards, providing extra strength and therefore accepting higher lateral loads. Both types are primarily used in tool & cutter grinding.