der schmied Posted July 24, 2012 Share Posted July 24, 2012 Hey guys, I am new to the forum and new to smithing. I am blessed to have easy access (about a 50 yrd. walk) to a ton of spring steel, and would like to forge a few punches and chisles. As far as punches, Im sure this is a simple, classic newbie question, but should the tip be pointed and how steep should the taper be to the final "punch size"? Thanks for any and all assistance in this matter. Quote Link to comment Share on other sites More sharing options...
der schmied Posted July 24, 2012 Author Share Posted July 24, 2012 Ok, I just found the intro to tools post on the tool ID section. I appologise for part of my question being asked that I could find the answer to myself. Have patience with me, Im still learning the site! :D The punches shown there dont APPEAR to have pointed tips. I am howevre, still a bit foggy on the taper to the punch size. If I was making, say a 1/4" punch, how steep should the taper be, if any? Quote Link to comment Share on other sites More sharing options...
Frank Turley Posted July 24, 2012 Share Posted July 24, 2012 You could make one out of maybe 1/2" round or 5'8" round. U.S. car coil springs are often close to 5/8". A two to two and one half inch long taper would be about right. The punch will have a flat bottom, and for a 1/4" hole, you might make the diameter a little less than that. Lots of things are happening when you hot punch a hole. There will be some draw on the entire bar; it will get longer. The bar will get a little extra width transverse of the hole site. You will be compressing metal in the hole itself. Some shear will take place, but there may be a little "punch suck-in" at the same time. The suck-in is a slight depression of metal all around the hole. Normally, when hot punching, there is a forepunch side and a back punch side. You start on one side and drive the punch a little more than half way into the material. Then you flop the piece, locate where to back punch, and drive the burr out from the back side. The burr will be small because of the compression of the metal. The burr will look like a little biscuit. Quote Link to comment Share on other sites More sharing options...
Ratel10mm Posted July 24, 2012 Share Posted July 24, 2012 I was taught 8 degrees for punches iirc. Quote Link to comment Share on other sites More sharing options...
Francis Trez Cole Posted July 24, 2012 Share Posted July 24, 2012 first you want to know what are you punching for is it a design or is it a mechanical connection point? and how thick is the metal you want to punch? if you have a bunch of spring look what is out there for sale and copy after a while you will know just want you want. if I wanted a 1/4" hole I would have a taper punch and a 1/4" drift. try not to over think it. I have seen many styles of punches from hand held or ones held by tongs or even a handle on them. you will have to figure out what works best for you. Quote Link to comment Share on other sites More sharing options...
der schmied Posted July 24, 2012 Author Share Posted July 24, 2012 Thank you for the info guys! Im gonna try to hammer a few out this week and post here for your review/critique! Quote Link to comment Share on other sites More sharing options...
David Gaddis Posted July 24, 2012 Share Posted July 24, 2012 good luck on your new hobby. When comparing punch press dies to hand held ones there is a drastic difference. The suggestion for a nice taper is well taken. Preferrably to to allow shock and bending to an acceptable ratio. The machine units a rather short stocky things...but they have depth comtrol! When you learn to drive the punch through hot metal you will learn just how much "umph" it takes to clear the hole out and yet not keep driving the punch so very deep. When the punch continues into the hole you may consider it a drift. In the next few days you will experience a whole lot of things. Be on the lookout for a cold cut end or birds mouth. Look in the books and you will notice that is not good. Many time it is remedied with cutting the length of punch material whit the hot cut hardy. Also...it you are punching hot material do not worry about heat treatment...as the hot metal will change the treated area. Heat treatment will be another lesson that too will be rewarding when done correctly. Carry on Quote Link to comment Share on other sites More sharing options...
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