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

Forge it to shape. Forge temps will negate any heat treating, so no need to anneal.

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.

Biggun does have a valid point

while you are at it, look up working with M2, it is not recomended for a first try with a tool steel.

Well thanks for the responses.  The margins are in perfect condition.  I guess I will try to sell it.  So if I were to purpose buy tool steel suitable for a hardy cut-off tool, what steel would I ask for?

 

David

Got any oil wells up your way?  Sucker rod

 

Got any cars up there?  Leaf or coil spring

 

If you must buy new----4340, 4130. 5160   most hardy tooling needs to be tough rather than brittle so medium over high C.

Can't go wrong with used jack hammer bits

Depends on what size hardy, and what you are making. Mild steel will work for many of them.

a good quality drill this size would cost a fortune, you may be best off trying to sell it.

over 10 years ago I paid over 250 uk pounds for one ( about $350 US )

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