to harden forging hammers or not ?

[basher]

After my first forge in I went round all the hammers in my school and tempered the heads back as I had a couple of anvils trashed with hammer marks . since then I have made all the new "japanese "style blade smithing hammers that we use in a normalised state an have not noticed any problems with them .
I have made a few extra hammers to sell and was wondering what your opinions were on weather to harden them or not. My own personal hammers are still hard and I notice no difference in the function when working hot metal .
what do you think .
All the best owen

[Frank Turley]

In the long term and with fairly constant use, perhaps two to ten years, the face of a forging hammer may flatten slightly or even hollow. After hardening, I temper my hammer faces to a dark straw (240ºC) by putting a 22mm square, snug fitting, turned-eye over the face. The eye is at a welding heat. My hammers are of medium carbon, 0.45% carbon content, which I harden at a cherry red by agitating in water. I never harden the eye. The dark straw temper is on the "hard end" of the tempering rainbow, the attempt being made to prevent any future flattening or hollowing.

http://www.turleyforge.com Granddaddy of Blacksmith Schools

[thingmaker3]

Those specific anvils had never been in a fire, had they?

[Ratel10mm]

I was there Thingmaker & I suspect it was far more down to amateurish hammer control (there were a number of blokes very new to forging, inlcuding me & Basher can't be everywhere) than bad anvils.

I hope that wasn't me that damaged them mate. :o

[Dave Budd]

I've been using the machinist hammers from Cromwells for that last 6 years and I like the fact that the faces are soft. Like Owen I've had my anvils dented by misplaced blows from harder hammers and I for one prefer to redress the face of a hammer than an anvil! I keep most of my hammers cleaned for finishing work with, but one is used for most of my work and after a about 5 years it has mushroomed to the point that it has been ground back twice (it's about 1/4" wider and shorter than when new), the face is also flattened and lopsided where it's taken abuse.

Students frequently hit my anvils and the new anvil I bought a couple of years ago is still soft enough to mark with these hammers, though my nice old one is harder and stands up OK. I don't know how hard the hammers from cromwells are (I'll try and remember to check that tomorrow) but they are harder than normalised EN8 would be. I think I would give my students softer hammers to protect my tools; keeping harder faced ones for striking chisels and punches and for general drawing of stock. I really only get dents on my hammers and anvils at the edges when forging blades down.

[rthibeau]

IMHO, if a hammer mushrooms over time, it is too soft. Any hammer will ding an anvil if hit hard enough and off hot steel, soft anvils obviously get worse than hard anvils. At best, it's a compromise between hammer and anvil unless you can get both to the exact same hardness. The best one can do is not hit the anvil bare but have hot steel in between the hammer and anvil = perfect hammer control. Absent that, refacing a hammer is cheaper and easier than refacing an anvil, so I guess that puts everyone back at square one. Temper your hammer to match your anvil?? All will be different.