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I Forge Iron

Annealing This Large Twist Drill


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So I picked this 2"/53mm drill bit up at the scrap yard.  (I really do not know why it was scrapped.  It is nicked at the cutting edge and they tried, not very well, to sharpen it but otherwise it is in excellent condition.) 

 

Anyway, I want to use it to make some hardy tools. I thought I would  I have not worked tool steel before.

 

My plan is to work the shank into a hardy cutoff tool. 

 

Do I need to anneal it before I cut the shank with a zip cutting wheel (angle grinder)? 

Do I need to anneal it before forging? 

 

What is the process for annealing?  Do I simply heat it to red or yellow and let it cool in the gas forge?  I don't have a bucket of ash or vermiculite.  I wonder if one option would be to get it to the proper colour (red? yellow?) and then just shut off the forge and shove some cerablanket (kaowool) in the forge door to help retain the heat. 

 

Ciao,

David

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Look on the shank to see if you can see HSS on it. Most large machine drills like that will be made out of High Speed Steel. Here is my suggestion, sell it, and buy some other stock. If the margins haven't been wiped out, it can be resharpened.

HSS is not sutible for hardy tools, very brittle, and difficult to work with.

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Hi David,

 

I made my current hot cut hardy from a scrap pickaxe. Easy to find (around here), its material is easy to work with, and it's tough enough. You just cut the blade part off, straighten it, widen the blade-to-be, tighten the shank part to fit the hardy hole, normalize it, file or grind it to final shape. That's it. (I even made a square drift from the spike of the same pickaxe - so double joy.)

 

Best wishes to you.

 

Gergely

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