A drill bit of 20 mm diameter rotating at 500 r.p.m. with a feed rate of 0.2 mm/revolution is used to drill a through hole in a mild steel plate 20 mm thickness. The depth of cut in this drilling operation is
A. 0.2 mm
B. 10 mm
C. 20 mm
D. 100 mm
Answer: Option C
This Question Belongs to Mechanical Engineering >> Manufacturing And Production Technology
Depth of cut in drilling = Dia of drill ÷ 2
Depth of cut in this case = 20 mm ÷ 2
= 10 mm
Your answer is wrong.
20 mm is the depth of hole not depth of cut . Depth of cut is always half of dia of drill.
(20+20)/2 = 20mm
Here it is (D+t) /2.