GATE 2024 ME – Question 62
A blanking operation is performed on C20 steel sheet to obtain a circular disc having a diameter of 20 mm and a thickness of 2 mm. An allowance of 0.04 is provided. The punch size used for the operation is ___________ mm (*rounded off to 2 decimal places*).
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Correct answer: 19.82 to 20.02
Explanation
In blanking the piece that is cut out is the product, so its size, 20 mm, is the die opening, and the clearance is taken off the punch. The allowance of 0.04 mm is the clearance on each side, so the punch diameter is $20 - 2 \times 0.04 = 19.92$ mm.