Dull white

White

Bright white

Bluish grey colour

Grain size

Type of abrasive

Grade

Structure

Durability

Cheaper in cost

Surface finishing is fine

Least coefficient of expansion

To form molter slag

To supply the oxygen

To burn the carbon in coke

To increase the melting point of ore

Depth micrometer

Inside micrometer

Outside micrometer

Screw thread micrometer