Annealing Drill Rod

[Nhgrants]

I bought some 5/16 drill rod to make a scraper type of tool. I heated to bright yellow and let it air cool.
This did not appear to soften it at all. A file would just skate off it.
I had done the same thing with a chain saw file. Once air cooled I could shape it with a file easily.
Is there something about drill rod that makes it difficult to anneal?

[rich pierce]

Really sounds like you might have A2 air hardening steel.  I’d try a slow cool in hot coals dying down to ashes after reaching critical temp.

[Bob Roller]

Really sounds like you might have A2 air hardening steel.  I’d try a slow cool in hot coals dying down to ashes after reaching critical temp.

I agree with Rich. Probably A2 air hardening steel.Try annealing as he suggested.

Bob Roller

[David R. Pennington]

It likely is air hardening. Air cooling likely too fast for lots of steel. A bucket of wood ashes works good as insulator to cool slowly. It’s a good idea to preheat the ashes. Just heat a big chunk of iron and bury it before you put the steel in. Then let them cool overnight. Some folks use vermiculite. I was trying out some new coal a while back and had forged a small tool. I just buried it in the forge fire and didn’t break the fire down. Figured the fire would die and everything would cool down slowly. Went out next morning and found fire and my tool still red hot! I discovered this particular coal was self motivated!
Last night I left a small tool I forged in a large coffee can with ashes and set the whole thing in the hot forge after I broke down the fire. It was well anealled when I checked it this evening.
I got a hold of some commercial power hack saw blade stuff once that I was never able to anneal no matter how hot or how slowly it cooled.

[D. Taylor Sapergia]

I had a blank tumbler once that I needed to thread for the cock screw, but a new drill would not touch it.  I tried every method and cooling medium there is to no avail.  Finally, I built a little birch fire in my yard, heated the tumbler bright red with a torch and threw it into the coals.  I retrieved the tumbler when the fire was cold, and now the steel cut like butter.

[Bob Roller]

Dry,warm sand will also act as a slowing down medium for annealing.
A coffee can full of it with a cavity in the sand has worked for me.
After the long hold of red hot drop the part in the cavity and immediately cover it.

Bob Roller

[Metalshaper]

I use lime to slow the annealing time. a can with a about 5 pounds of it works nicely for me.   I preheat a piece of metal with at least 2-3X the mass of the one I'm annealing.. this gets heated low orange and is shoved in the lime with a  handle piece sticking out. I then heat the real part to non-magnetic/cherry red. I use the part sticking out, of the preheat metal, as a handle and try to lift the lime and create a pocket in the heated lime. the 'real' part gets wiggled into the hole and the lime allowed to shift in and seal the works. the preheat metal is also shoved back in along side of the 'part'  to continue adding some heat and slowing the process.  walk away and leave overnight.

Did this on a piece of metal that was pretty thick.. about .5 X 1 x 2".. next morning I went to grab it out and it still had enough heat in it to be uncomfortable! ( preheat metal was something 1 x 2 x 6" )

My experience anyways??

Respect Always
Metalshaper/Jonathan

[JBJ]

The powdery ashes saved from the charcoal grill also work great to slow the heat loss.
J.B.

[P.W.Berkuta]

I have use vermiculite and also sand from the garden center with varying degree of acceptable results. I've heard that cat litter and speedy dry have been used by some successfully - I've not try it so I can't comment.

[longcruise]

I don't know drill rod from a fly rod, but it would seem that it would be in an annealed state from the manufacturer meant to be worked and then heat treated by the end user.

[FDR]

Everything you ever wanted to know about drill rod:
https://www.onlinemetals.com/merchant.cfm?id=267&step=2&top_cat=1354

Fred

[45-110]

generally drill rod comes annealed, but music wire come hard. A2 is great but can give you fits working it, sometimes it gets hard just from machining heat it if you are not running coolant.

[David R. Pennington]

Lime works well but can be corrosive if you happen to forget a part left in there a while, (not that I would ever do that).