I need to make my lead much harder

[acsteve]

I know that adding hard shot will increase the antimony content and substatually harden lead. But how much should I add to maximize hardness. Oh, I'm actually not making boolits with this so it really cant be too hard. So I have come to the lead experts at the forum.

[grumpy one]

Refer to Frances Weaver's chart, attached. As you can see, a straight lead-antimony alloy can reach 18 BHN without heat-treatment. This would require at least 12% antimony. Further increases in antimony content beyond that level have almost no effect on hardness. You can make much harder alloys by adding some tin as well as antimony, which can get you into the typemetal alloys. Hardness of those goes all the way up to 33 BHN air-cooled. However depending on how long you need your alloy to stay hard, it is likely to be much more convenient to heat treat a low antimony alloy. 4% antimony is enough to get you 32 BHN with heat treatment, but the alloy will soften somewhat over time.

[Gunslinger]

Then what are you wasting good lead for, if you don't mind me asking :grin:?

If you use wheel weight alloy, the trace arsenic in it will allow you to harden it in water... and I think antimony has the same effect... correct me if I'm wrong.

[Shiloh]

+1 to Gunslinger. What are you making??

Shiloh

[imashooter2]

Using "hard shot" and lead, you will maximize hardness by adding 100% shot. After that, grumpy one has good advice. Here's a better picture of the chart:

http://home.comcast.net/~imashooter2/pictures/fig8-sm.JPG

[acsteve]

Thanks for the great info. Need to shim a no wear part, which I cant weld on an old tractor. If it lasts for a few years, that will be a few years longer than I will need it. thanks

[docone31]

I would make the part out of zinc.
Definately harder, and much less politically incorrect.
A blend with zinc and lead works for me with paper patching, hard as all get out.
If there is no wear, zinc.

[Rusty W]

I've used regular ole shim stock. Some is brass, some is stainless, some is plain ole carbon. There is a supplier local here called Shamrock bolt and screw and they have a variety of it. Grainger may have what you need also. I used to work in industrial refrigeration and some of the recip compressors were very big and out dated. They used a rod and piston about 4' tall. They had a 12" bore and 12" stroke, some were bigger. Sometimes we had to fix them with what we could make work because parts were no longer available. We've even used leather as a shim for rod inserts....