Fastener Facts
PDHonline Course S247 (2 PDH) Fastener Facts Instructor: Semih Genculu, P.E. 2012 PDH Online | PDH Center 5272 Meadow Estates Drive Fairfax, VA 22030-6658 Phone & Fax: 703-988-0088 www.PDHonline.org www.PDHcenter.com An Approved Continuing Education Provider www.PDHcenter.com PDH Course S247 www.PDHonline.org Course Content Although selection of bolts, nuts and washers may appear as a difficult task, in reality it is quite simple as long as factors such as operating temperature, service environment, corrosion, vibration, initial clamping load (torque) and cyclic loading (fatigue) are carefully considered. If the main function for the fastener is strength, then steel is probably the most appropriate type to use. If the service environment is corrosive, then either steel with a protective coating or stainless steel or a nonferrous alloy should be considered. If magnetic permeability is important then an austenitic stainless steel, aluminum or copper alloy should be used. If high electrical conductivity is needed, aluminum or copper fasteners can be used. For weight saving situations aluminum is the main solution. If high strength is coupled with weight consideration, as in aerospace applications, then titanium may have to be selected. For high and low temperature service stainless steels or superalloys (with high alloying additions of nickel, molybdenum, cobalt, vanadium etc.) should be utilized. Fastener Materials Bolts can be made from many different materials but most are carbon, alloy or stainless steel. Titanium and nickel alloy bolts are also used in aerospace applications. Carbon steel is the most common fastener material. Steels are usually zinc plated (galvanized) to resist corrosion.
[Show full text]