The strength of a steel is mainly determined by the content of iron and carbon. Especially the carbon content is essential for hardening the steel. That's why high carbon steel is used in applications where strength matters. Tools are made from high carbon steel and other ingredients like chromium and molybdenium. For steel to harden it needs to have a minimum of 0.8% carbon, and that's the low end. Bolts are treated similar, depending on the grade, but are not necessarily hardened, but strength is achieved with certain ingredients. Stainless steel however doesn't contain iron or carbon, especially not the iron part, which makes it non-rusting. Stainless steel usually contains chrome and nickel, which gives it a certain strength, but the main target is non-corrosion. The most popular stainless steel is the one with 18% chrome and 8% nickel, or 10% nickel. This is the same stuff used in your silver ware and pots and pans and kitchen sinks. This steel mainly just looks good and has a certain strength, but is not suitable where high strength matters. Also because it's more tough than hard, makes it a bi*** to machine it, causing the machining tools to require alot of cooling, or they burn up rather quickly. When torquing SS bolts down hard, they tend to stretch and relax, requiring them to be retorqued again and the same thing happens again. Usually the third time they stay torqued, but it's not nearly as high as a head bolt needs to be. Eventually the material stretched enough to just break. ALso when using SS bolts make sure you lube them a little. NEVER put them in dry, especially not aluminum. The seize VERY fast!srinath wrote on 07/07/09 at 07:45:10: