keel alloy mechanical properties?

[water addict]

OK sailboat experts out there,
What sort of mechanical properties are used in keel alloy analysis and design? I'm specifically curious about Emodulus, allowable stress, yield stress, ultimate strength for typical keel lead alloys, ie. lead-anitmony 3%.

much appreciate if anyone could forward those numbers to me.

[water addict]

No takers? Someone in boatdesign land must have that info...

[Skippy]

I have a couple inklings on this subject, but that's about it. One guy building a back yard boat believes the lead should be alloyed with 4% antimony for hardness. Apparently X-ray shielding doesn't have the antimony, but automotive wheel weights do.

Other than that, I would only want the structural materials to be very very strong.

[Ssor]

Lead keels are usually such thick sections that the only concern anyone would have is the ability to hold the cast-in bolts. If the lead is exposed, then grounding on rocks gouges the lead but lead is not used for its mechanical strength. That's why you never see lead center boards, usually wood weighted with lead, or steel or bronze center boards.
Even alloys of lead are only relatively "hard". Zinc is much harder and you could chisel marks in any lead alloy with aluminum.

[dougfrolich]

Lead with 3% antimony has a Tensil Strength of 4700psi, an elongation of 16%, and Brinnel Hardness of 9.1. 5% antimony TS= 6360psi, elongation 29%, and hardness of 11.

[water addict]

Originally Posted by dougfrolich

Lead with 3% antimony has a Tensil Strength of 4700psi, an elongation of 16%, and Brinnel Hardness of 9.1. 5% antimony TS= 6360psi, elongation 29%, and hardness of 11.

Gracias,
Any numbers for Emodulus or Yield (0.2% offset I guess)?

[D'ARTOIS]

If you are not satisfied with your keel(weight) then take low radiance Uranium,
whatever the chemical composition of lead, you are not going to better it.

[Ssor]

Originally Posted by D'ARTOIS

If you are not satisfied with your keel(weight) then take low radiance Uranium,
whatever the chemical composition of lead, you are not going to better it.

Kinda hard to come by depleted uranium though.

[FAST FRED]

A visit to Bagdad should solve the Depleted Uranium supply source problem.

Scrap lead has been used for centuries , still the cheapest option is steel , although it needs to be a bit wider to have same CG. location.

Steel is probably the strongest to run aground with,

FAST FRED

[water addict]

OK, thanks for the clever quips-
Any #s for Emodulus or yield?

[dougfrolich]

E= 2030 ksi for pure lead
Tensil Yield Str. 1160 psi ( 2% offset)

[water addict]

Thanks mon