How to reverse heat treat?

[Chiro75]

Well, it seems like waiting to drill holes after heat treat, even though I was only edge quenching, was a big mistake. On the larger blades (5" OAL), I can probably wrap the blade in wet rag and anneal the handle a bit to soften it up, but I have four knives that are less than 2" OAL that I don't think this will work on. They are already quenched and tempered. Is there any way to "reverse" the heat treat and bring the knives back to the annealed state, drill holes, and then re-heat treat them, or should I just eat the cost of a few 1/8" bits, get my holes done, and learn my lesson for the future?

 

[Bruce Bump]

I will anneal them for you if you will adjust my neck. You may try to spot anneal the hole by heating to red and slowly turning the flame down. People use carbide drill bits also for these hard spots

 

[lively]

Wash the tang to remove all oils. Put a nail or a extremely dull drill bit in you drill press at high speed and slowly apply pressure to the spot you want to drill. The friction will heat the spot to cherry red after a minute or so. Then slowly relieve the pressure so it slow cools. This will make it soft enough to drill easily with a quality bit into simple carbon steels. I don't know if it would work for air hardening steels though.

 

[Normark]

Steve....

Get some brass round stock whatever size you need,, and cut a few pieces, making sure they are square and will stand up on their own...

Heat the small pieces of brass until cherry and stand them up where you want to drill..
When they have air cooled the spots where the pieces were should be mild enough to drill.

Works well...

ttyle

Eric...