Brass

Cast iron

Mild steel

High carbon steel

Rolling

Sliding

Dragging

Use a trolly

Cooling the metal

Heating the metal slowly

Hold at a given temperature

Heat and cool the metal as soon as possible

To increase softness

To with stand wear resistance

To withstand heavy load

To decrease the brittleness

Oxygen valve in cylinder

Oxygen valve at blow pipe

Acetylene valve in cylinder

Acetylene valve at blow pipe