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drifting holes is hard


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Drifting looked like one of the simplest things to perform, and yet I'm having zero luck. My holes always end up off center, or oblong, or just plain too small.

I'm trying to make a bottle opener out of 1/2" rebar... what's the biggest size hole you can drift in 1/2" rebar out of that material? (Maybe I just need to use more steel?)

Also... I don't have a tapered punch with a large enough diameter and I'm not sure how to use the anvil horn to make the hole bigger. How do you hammer the iron over the horn without ruining the whole thing?

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There's not much room for error with 1/2 inch rebar. You would be better starting with flatbar about 1/4 by 3/4  or 1/4 by 1 inch. 

Then carefully centerpunch  to mark the exact midline . Do this cold and don't trust your eyeball guestimate, measure it carefully. 

Your better off slitting or punching a slot and expanding it with a drift. A drift isn't too hard to make. Draw a long square taper and then round it off. Mild steel is good enough unless you're planning to use the drift a lot. Suggest you take a look on youtube and see some videos how to make a bottle opener. 

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I think you just answered your own question.  You need a bigger punch.  If you move fast you can drift a piece open a long way, but once you get the ring thin, it cools very fast, so you probably only get one hit per heat.  Get as close to your forge as you can or use a torch, and a helper makes it go better.

If your hole is off center, you need to correct that early, hammer the thick area over the mandrill or on the horn.

You can't use the horn to punch the hole ( you can, but it's a lot more work) so start that with a flat end punch or a drill.  It's also hard to use the horn as a drift.

 

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I highly recommend getting and reading the first volume of Mark Aspery's books " http://www.markaspery.com/School_of_Blacksmithing/Book_1.html "  If you're slot punching round, you're going to always have issues with alignment, best to punch in a 3/4 inch swage.  Both the making and the using are covered in great detail in the book.  The book is supported with a number of videos, here's the one on forging a swage block: https://www.youtube.com/watch?v=pxTdbC5MLRQ

Edited by Gerald Boggs
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Interesting points. I thought I saw someone on Youtube drifting with a slot punch and then opening it up a drifting further on the horn. I really think that's a stupid way to do it though, now that I stop and think about it.

I'll try with some flat bar - the rebar is very unforgiving.

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  • 2 weeks later...
Quote

 

"You need a bigger punch.  If you move fast you can drift a piece open a long way, but once you get the ring thin, it cools very fast, so you probably only get one hit per heat.  Get as close to your forge as you can or use a torch, and a helper makes it go better."

 

That'll definitely help a lot. Thanks, Geoff! Will take note of that as well.

 

By the way, just in case anyone’s interested, my cousin Jack is selling a few 18 Inch truck Wheels. If anyone’s interested, feel free to PM me.

Edited by Robert Albert
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