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View Full Version : shop trick - recovering from holes punched undersize



metalmagpie
05-16-2011, 03:42 PM
I do a lot of fabricating, not so much machining anymore. Today I was punching a line of 3/8" holes down a 1/8x2" strip which I'd carefully layed out and centerpunched. I centerpunch the hole locations so I can find the tit on the end of the punch and that way the holes go where I want them. Otherwise it's a crapshoot because I can't really figure out what's going on. I was nearly done when I realized to my horror that I'd punched all the holes 1/4"! This of course meant that I couldn't use the centerpunch trick, so I first thought the workpiece was ruined.

Then I thought of something. I carefully collected the slugs I'd punched out, took them and the workpiece over to the anvil, and using a hammer, drove them into the holes. They were of course centerpunched already, so then all I had to do was put the correct punch and die in the machine (in this case a Whitney No. 10 hand punch) and repunch the holes. They probably aren't perfectly located, but you can't tell by eye. I'm happy 'cuz I didn't have any more stock and steel is expensive now ..

metalmagpie

RB211
05-16-2011, 03:47 PM
Why not make a new punch with a cone to auto center the punch?

strokersix
05-16-2011, 04:37 PM
Because magpie would be done with the project in less time than it would take for you to turn a punch blank.

Mcgyver
05-16-2011, 06:07 PM
way to think on your feet....you may just have invented a new kind of tool .... sacrificial undersized hole dimple locating transfer punch blanks :D

wierdscience
05-16-2011, 06:22 PM
That's basically how I punch the hole bigger in skillsaw blade for use on a weed eater,

Punch out a 5/8 slug and tap it into the sawblade,then use the punch center mark to center the 7/8 punch.Works every time.

jcon
05-16-2011, 06:22 PM
Nice Save Magpie