
231Machining by Abrasion
The material to be ground: The material to be ground affects the choice of the
abrasive type, grain size, and wheel grade as follows:
Abrasive type: To grind metallic materials, Al
2
O
3
grinding wheels are
primarily used (steel and its alloys). For nonmetallic materials, SiC wheels
are used if the hardness is 800 Knoop or less. SiC is also suitable for grinding
gray cast iron, aluminum, copper, glass, cemented carbides, and ceramics.
Diamond wheels are used to grind the harder nonmetallic materials.
Grain size: The high-speed grinding of hard, brittle materials uses a
medium to ne grain size. Soft and ductile materials a ...