Working with air hardening steels specificly H-13

mattmaus · Post by **mattmaus** » Fri Oct 20, 2006 9:41 am

Anyone have any experience with this?

Recently I've been thinking about what I want out of a dishing hammer, and the reality is I'm probably going to have to make it or have it made.

I'm thinking about H-13 because I understand that it is "teh r0x0r$" for hot work tools, and I intend to use it for hot dishing.

My question is do I get just one heat?

Do I work it slow keeping it hot? e.g. heat tap tap heat more tap tap..

If I have to stop to pee/chase dog/chase kids/chase neighbors/chase neighbors peeing kids/etc. and let it cool it's basicly hard at that point. If I heat it again will I still be able to work it?

Signo · Post by **Signo** » Fri Oct 20, 2006 10:03 am

Why not just anneal it and have it hardened after forming?
If you don't allow it to cool down in the open air, but maybe under hot sand, i think you can have it in a workable status.

mattmaus · Post by **mattmaus** » Fri Oct 20, 2006 10:08 am

From what I recall, to anneal H-13 you start it at about 'critical' and drop the temp by 100 degrees every couple hours. Then burry it in sand when you get it near the 900 degree mark. I'd have to check my references to be sure. But from what I recall it pretty much takes the betterpart of a few days to anneal properly.

Because it doesn't like to soften up at all easily is probably one of the reasons it's favored for hot work tools.

Cet · Post by **Cet** » Fri Oct 20, 2006 10:16 am

enerally H designation steels will have a high hot hardness relative to other types which translates to requiring greater effort to forge. If your intended use is a hammer for hot work I think the "H" designation steels would be overkill and not worth the extra effort. Hammers aren't usually in contact with the workpice long enough to soak up enough heat to screw up their temper and you can always put them head down in a slack tub between forge heats. It might be a good choice for stakes though as they do tend to build up heat and can't be cooled as easily as a hammer head.

mattmaus · Post by **mattmaus** » Fri Oct 20, 2006 10:31 am

possibly....

Bigest reason I considered it is that I burned the crap out of my hand the other day after hot dishing a pair of helmet bowls, tossed the hammer in the rack, came back half hour later grabbed the head of the dishing hammer, and dropped it RIGHT quick.

Basicly I've decided what I want out of a dishing hammer pretty specificly, and don't want to have to re-make it, or have it re-made, except possibly in different sizes.

I'm thinking a 2" face with an 8" radius and softer corners, that sits at least 4-4.5" off the handle, and a weight of about 24 oz.

Cet · Post by **Cet** » Fri Oct 20, 2006 10:39 am

The heat required to burn your hand is a lot less than that required to pull out a temper on most tool steels.

Why are you hot dishing halves anyway? I'll sell you as many as you want cheap

mattmaus · Post by **mattmaus** » Fri Oct 20, 2006 10:43 am

Thought about that....

Unfortunately.... I don't think that your bowls would help me with but 1 out of 4 things I make.

and.... I kinda like making my own stuff...

and... it gives me something to do on cold days when I don't feel like getting frostbiten fingers from the little hurricanes air tools make.

PM inbound anyway.

Thomas Powers · Post by **Thomas Powers** » Fri Oct 20, 2006 11:00 am

Forging of high alloy steels: most high alloy steels havbe a limited forging range, too cold and they're d***'d hard; too hot and they cottage cheese on you.

Even at the correct temp they will take more force to move the metal.

Other than that they forge like steel. work them inside their temp range and to harden let air cool. Note that the *draw* temp for some of the high alloy steels is just about glowing.

Generally in blacksmithing we reserve things like H13 for cutting tools and punches where fairly small cross sections will be in close contact with hot steel for an appreciable ammount of time and we'd like the tools to stay hard even when quite hot---BTW the stuff is expensive!

The drawing temp for a hammer of regular steel should probably be above the ignition temp of paper. If you are getting your hammer that hot it's a safety hazard and will be charring the handle out of it to boot!

So if you want to---go for it!

Thomas

RalphS · Post by **RalphS** » Fri Oct 20, 2006 6:21 pm

When working air hardening steels make sure to do all the forming without cycling the metal between orange heat and about 300 C. You get multiple heats, the steel will austenitize while you're working it, and will harden once it drops below the martensite start temperature, around 250 C or so.

So if you're working something into a long shape, start in one end, keep it hot, work towards the other end and finish everything before letting it drop to low temp. Working from one end to the middle, flipping it and working from the other end to the middle again may have you trying to work a hardened piece of heat resistant steel at the point you meet in the middle.

If that happens, put the entire piece in a fire, heat carefully to forging temperature and keep it there for, say, one hour, and carefully try to work it again. If you don't, things are likely to break.

mattmaus · Post by **mattmaus** » Sat Oct 21, 2006 12:46 pm

Thanks for the pointers guys. Greatly appreciated.