Dremel Fix ?

[trbig]

And again... carbon is absent from your statement, the whole determining factor. Yup... It's me that's the stubborn one.

And yes, I will be trying this. With carbon.

[tarzan]

Good luck.

[TomB]

I have a bit experience with hardening metals.
BTW, I will try and remember to take my old gears to work and check hardness, I ground on them too, so I can test both, an area I ground on, and an area that I haven't ground.

Hardness testing of case hardened metals is generally not done, you get a false reading, the outer skin may be hard but sometimes only a few thou thickness and as hardness testing is indenting the metal you indent into the soft inner.

Kasenit powder can be used for rolling cherry red steel into, but better results are achieved if using a fire box, a cast iron box full of Kasenit with the metal inside and the lid fire clay sealed, and left in a hardening oven for a few days at 850oC. One place I worked used crushed carbon, much like BBQing charcoal crushed into a rough powder in the fire box, the longer you leave it the deeper the hardness.