Hammer Dies

[Will. K.]

I have a couple of questions regarding power hammer dies. Down the road I’m planning on machining some dies for a 50-75lb home built power hammer in the works and possibly a set of flat dies for my 250lb Beaudry.

Is grain direction in the die material important to account for when machining power hammer dies?

I’ve been told that 4140 and 4340 are good choices for die material. What about some of the grades of tool steel like A-2, D-2 or S-7 assuming I have them properly heat treated? In general are there any of the alloys to stay away from due to wear and/or safety reasons?

Thanks,
Bill

[bigfootnampa]

S-7 and D2 would be topline for die uses. 4140 and 4340 would be usable economical choices. D2 would be my choice as it comes a bit cheaper than S-7 though the S-7 may well be the best choice for long wearing use. For experimental dies and short-run dies you will likely get by just fine with the 4140 or 4340. I don't feel quite qualified to advise you regarding the heat treatment but as the D2 will air harden some it may need no heat treatment, or maybe just normalizing.

[clinton]

I used 4130 for my dies and they are holding up nicely. You can get it in a heat treated condition, 53 RC is what I ended up with. It can be machined with no problems

[Will. K.]

I see A-2 and D-2 drops for sale at auction from time to time but I don't see larger 4140 or 4340 to often unless its round bar. I'm just trying to plan ahead so if I see some suitable size stock for sale at a good price I can get it.

[nonjic]

For the industrial stuff grainflow is marked on the pre-ht stock we machine them from. (but I cant remember off the top of my head which way it sposed to go ) TBH I dont think it will make any noticeable difference in a hammer that is in 'light duty' - ie a few hours a day maximum use.

Its not really in the spirit of making your own hammer but it might be worth (ie cheaper!) buying a set of dies from one of the hammer vendors. I think (citation needed) that John Larson buys his dies in from one of the turkish hammer vendors? I know James Johnson carries a large stock of dies for the Anyang hammers, and Jock Dempsey on Anvilfire mentioned the other day that he has bought in the dies for his homebuilt hammer project from Big Blu!

Whatever you decide I would err on the side of softer dies than hard, its a lot easier to reface them than to have a fractured lump of die removed from yourself (im not scaremongering, it does happen!)

[patrick]

I would strongly advise against using either the A or D series tool steels for hammer dies because they lack the toughness of grades like 4140, 4340, S7 or H13. As Stewart noted, 4140 makes very good dies and is very economical. 4340 is the material of choice for the open die hammers we have at work and in our case the hardness is kept in the upper 40's HRc. For smaller hammers a harder die can be used, but you need to be careful not to make any die too hard since you don't want it to spall or crack. I have friends with a 4B that split one of the dies during use. No one was hurt, but that is a very dangerous situation.

Patrick

[monstermetal]

I have a ton and a half of 4340 flat bar in 3"x 5" and 3.5" x 5". I've been getting $2/lb which is about 40% of wholesale for that size ( round bar seems to be cheaper)

4340 is much tougher than 4140 with almost twice the yield strength (and more expensive) I have many sets of dies made of 4340, 4140 and h-13. Personaly I think 4140 is too ductal for anything over 125lb hammer in a narrow die section but if your ok with dressing the dies from time to time it certainly will work and is less than half the cost of 4340 or h-13 or s-7. In a flat/large die set they will hold up longer. I don't have any s-7 dies but by all accounts it's probably the best or one of the better choices for dies that might work cold ( like chamfering cold bar or cold tooling)

[Nakedanvil - Grant Sarver]

I used 4130 for my dies and they are holding up nicely. You can get it in a heat treated condition, 53 RC is what I ended up with. It can be machined with no problems

Did you transpose the five and the three? 4130 won't make 53 Rc even water quenched. 35Rc is a common pre-heat treated hardness. 4340 is my all time favorite.

[Francis Trez Cole]

there is an other choice since you have not yet started. I am making a set of flat dies for my hammer and making hand held and spring tools that Clay spencer put together I found his system changeable and effective. He put out a free book on the Alabama forge site http://www.alaforge.org/Tools.html

[clinton]

Did you transpose the five and the three? 4130 won't make 53 Rc even water quenched. 35Rc is a common pre-heat treated hardness. 4340 is my all time favorite.

Well ya got me there Grant, the material is 4130, was going off memory on the RC 35 must be right. I can not find my notes now but the gut that sold me the material did give me the rc on it. I will try to go test it this week I do have access to testing equipment at the local college.
When I ordered the material I told the guy that i wanted 4140 and when it got here the invoice said 4130 so there may have been a mix up somewhere. They are holding up nicely so far, but I do not think that I will get any more die stock from that place, it was cut out of plate and looked like a banana on one side (too much machine work to square up)