Tool making advice

[Tris]

Hi, need to pick the collective brains here.
I want to make a couple of bead forming scrapers for woodturning. The plan so far is to get some annealed tool steel, 5mm x 10mm, drill hole of required diameter, cut through, relieve the edges. So far so good.
What should I do once the shaping has been finished? If it needs to be annealed again after working what's the easiest way to do this at home?
Grateful for any advice.
Thanks
Tris

 

[--Tom--]

If it’s not got excessively hot when forming no need to anneal/ normalise again.

If you want to heat treat it, you’ll need to have a way of heating it above the critical temperature (700-1200c). For simple carbon steels like O1 the curie point (where it becomes non-magnetic) is used as a good estimation of the critical temp.
If you look up a can forge or 2 brick forge this is easily made with a MAPP torch for heat source.
Once this temperature is reached you need to quench by cooling quickly, plunging into simple veg oil is suitable for this.

Following this you’ll want to temper the steel to bring the hardness down and increase toughness. As quenched you’ll have some black burnt on oil. Clean this off with a bit of wet and dry, and then you can temper in the kitchen oven. 220c for an hour should be fine. If you’ve cleaned the metal you can look for the oxide colours - a dark straw is good (there are charts on line which give more specific times and temps)

There’s more that can be said on this but hopefully the above gives an idea

 

[chaoticbob]

Tris, if you're planning on hardening the tool something which Tom doesn't mention is that it's better to harden the steel before making the cutting edge by grinding if you can. The reason for this is that if you heat the pre-shaped tool in a flame it's all but impossible to get the bulk of the metal up to temperature without overheating the thin cutting edge and degrading the steel. I learned that the hard way! In your case you will do better by drilling and halving to give your profile, hardening, then putting on the relief by grinding (a Dremel type tool with a silicon carbide stone will do).

As Tom said, there's more to it, just my 2p worth!
Rob.