to punch a .375 dia hole....

[smokehouse]

We are going to design and build a blanking die. If I want to punch a .375 dia hole in the strip, would I use a .375 die opening minus clearance on the punch?

 

[meterbox]

Tricky question. It really depends on the function of the hole. As a general rule, use a .375 dia punch & add clearance to the die. If the slug produced is the finished part, apply clearance to the punch. For reference, try "The Machinery's Handbook" or any die making book.

Hope this helps

 

[smokehouse]

Thanks, That is what I was looking for. The holes in the strip need to be .375. The slug will be discarded. So we'll go with a .375 dia punch and add die clearance.

 

[ornerynorsk]

In practical use, always add .001 to your punch. Your hole will shrink as soon as the punch comes out. This is especially important if you are using registry punches further along in the die.