have just finished a diagonal peen hammer and would like any tips for hardening. So far I have drawn a temper on face and peen to a light purple But feel this face could be harder. Will it 'case' harden with prolonged use?
would appreciate any comments thanks paul.

What kind of steel is it and have you hardened it yet? Tempering is takeing away a bit of the hardness that was acheived by hardening so it will not be brittle. Different kinds of steel need different kinds of heat treat,, Could help more if I knew more about your material.

Mail me at [email protected] and I will send you a doc on the subject

Case hardening, immersing it in high carbon materials at high temps for a length of time---sounds like you mean work hardening it and no it won't do a good job of hardening the face (either one).

With out knowing the details of what alloy and how the heat treat was done it's hard to guess what would help.

yes, sorry i did mean work harening! but like you say, ThomasPowers, this is the wrong road.
The hammer is actually an old lump hammer which i have reshaped, so difficult to give exact details of steel.
Before tempering, the whole head was heated to a cherry red then after quenching face and peen I Polished a spot on face and peen edge and at desired colour quenched whole head . Am i being impatient ? should repeat this process until i get desired result ?

I honestly like a soft hammer, but hey thats just me! Rather resurface a hammer than an anvil. I wouldn't worry all to much about it. Use it and if you think it needs to be harder/softer, then treat it as so.
Good Luck! :D

I like it. It's a nice hammer.

So reheat/quench and draw to a dark straw this time and see if that's a good hardness for your hammer. Standard procedure for unknow "junkyard" steels; though we often suggest you try it hard first as you can then re-temper softer without doing the whole redhot heat/quench.

Better soft and forgiving that a load of poorly bound shrapnel though!

yeah thanks for the input everyone. Starting to think maybe jumping the gun a bit! after using hammer a bit am getting used to the 'softness' and actually quite like it. Think i might make a few more and experiment a bit with my hardening technique.