Hello. I'm wondering if any of you can suggest a metal, or composite, for the ultimate mining/masonry work boot...
Normal steel toe work boots are rated for 1500 pounds, or a 75 pound weight dropped from 18 inches, both of which are equivalent. American, Canadian, European, and Australian standards are all roughly similar. After two weeks of searching, I believe no one makes a boot significantly stronger. The best I have found is a miner's boot, which has foot top and shin stainless guards, stainless steel toe, Kevlar stitches, leather over kevlar over gore-tex exterior covering. Fire proof and water proof, with a Kevlar liner. There is 7 ounces of Kevlar in each boot, plus the stitches. But even these boots are only designed for 1500 pounds. California regulations require fiberglass toe caps, because steel toes tend to rock backwards, under heavy load, and have amputated toes. Fiberglass toe caps are designed to shatter after 1500 pounds, and leave doctors more to work with. I have read about high tensile steel. The highest grade high tensile steel is said to have an 80,000 pounds per inch capacity. This steel is used for ship hulls, and dump truck liners. It's also extremely heavy. Titanium is lighter, but weaker than high tensile steel. 1 inch of high tensile steel has the same tensile strength as 2 inches of titanium, but the 2 inches of titanium will weigh about has as much as the 1 inch of steel. So, by weight, titanium has more tensile strength than high tensile steel. By volume, high tensile steel has more tensile strength than titanium. Almost double. Tensile strength is not the only factor for strength though. Glass has about twice the tensile strength of high tensile steel, but glass has no torsion strength, like iron, and carbon. I don't have data to compare high tensile steel's and titanium's torsion strength. So anyway, here's my problem. The largest granite slabs I work with are about 1500 pounds. 1500 pounds dropped at terminal velocity will become about 24,500 pounds of kinetic energy. To allow for environment temperature variations, uneven surfaces, and angled impacts, I want a boot with a 25 ton (50,000 pound) capacity. I can probably make a boot with a 'roll bar' out of the high grade high tensile steel, but it would be very heavy (maybe 8 pounds). I can also use titanium, but the boot would be very thick/large (maybe 4 pounds). Can any of you suggest a lesser known, surely more expensive, material that would be ideal for this project? I'm considering something like titanium with carbon added, so maybe the metal is the best of both worlds, but this will make the titanium more brittle. The material does not need a large plastic range, just enough to be able to handle moderate vibration and shock. Yield strength is the strength of something before it starts to bend. Ultimate strength is the strength before it breaks. The plastic range is the space between bending and breaking. A decent plastic range is needed to provide torsion/compression strength. For example, glass has double the tensile strength of high tensile steel, but glass has no torsion strength, so it's brittle. robert -- http://linuxfromscratch.org/mailman/listinfo/lfs-chat FAQ: http://www.linuxfromscratch.org/faq/ Unsubscribe: See the above information page
