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

Thread angle

Type of thread and pitch

Root and crest

Major diameter

Depth

External dimension

Angular dimension

Size of holes, slots and recesses