Shearing. Punch and die Ratio of rough area:burnished area increases with higher ductility Punch travel depends on the ductility or brittleness. –A brittle.

Shearing

Shearing

• Punch and die

• Ratio of rough area:burnished area increases with higher ductility

• Punch travel depends on the ductility or brittleness. – A brittle metal requires little travel.

Punch Force

• Punch Force = shear strength * cross-sectional area.

• Friction can affect this.

• P = 0.7 (UTS) (t) (L)

http://www.transvalor.com/index.php?rub=52&mo=3&so=63&sso=52

Shearing Operation

• Punching – slug is discarded

• Blanking – slug is retained

• Fine blanking

• Slitting

Shearing Dies

• Clearance usually between 2% and 8% of the shear thickness.

• Compound dies– Several operations on the same strip may be

performed in one stroke.

• Progressive dies– Multiple operation are carried out as the coil is

moved after each stroke.