In a rolling process, sheet of 25 mm thickness is rolled

In a rolling process, sheet of 25 mm thickness is rolled to 20 mm thickness. Roll is of diameter 600 mm and it rotates at 100 rpm. The roll strip contact length will be

Given : t₁ = 25 mm, t_f = 20 mm , R = 300 mm, N = 100 r.p.m

Angle subtended by the deformed zone at the roll center,

Q_i = √	(t_i - t_R)
	R

Q_i = √(25 - 20) /300 = 0.129 rad.
∴ Roll strip contact length = θ . R = 0.129 × 300 = 38.72 mm