Quote Originally Posted by ngwagwa View Post
A friend of mine makes knves for a living and was looking into induction heating for his workshop but he gave up on the idea as if induction heating was used for hardening the material had to be long soak annealed and the cooling time was too long.
The simplest way is a container full with ash, have done that and it works pretty well. Probably cools for a day or 2. Of course if the steel is more complicated temperatures must be pretty exact, modern powder steels and so, if i remember correctly.

Quote Originally Posted by ngwagwa View Post
Go for it but there is a big difference between annealing and normalizing.
Exactly, quick normalization if needed after the part is machined and grinded could be done , heat and leave at air.

If i work some material, i would study the documentation and recommended methods. There are also different types of annealing, if we look deeper, but as i said i have no reason for normalizing or annealing the material, when machined. I machine it with air cooling the bit so nothing heats and then belt grinder, same here.

In reality i wanted to make that from S7 steel as its the other steel perfect for the purpose due to the toughness, but can not find a sheet vendor in Spain. Probably some one sells it in Europe, but now with the covid... As its heat and leave to air harden.