Fasteners

Common fasteners include screws, bolts, nuts, and rivets. Studs are headless fasteners which are threaded externally. In this, one end of the fastener connects with a tapped part while the other end meets with a standard nut. The forms of bolt and screw heads vary with the usage of the fastener. Stud bolts, a term used for cut-to-length all thread rod, are used for: bolting together flanges, anchor bolting, as well as a general fastening.

A threaded bar or threaded rod is a long rod that is threaded on both ends; the thread may extend along the complete length of the rod. It is designed for the use of tension purpose. Threaded bar and rod stock form are often called all-thread. It is designed in different sizes and can have right and left-hand thread patterns. PTFE coated fasteners provides great corrosion resistance, a very low coefficient of friction, consistent tensioning and ease of installation and removal. Extensive testing and field use have proven that the future of the coated fasteners lies with Fluoropolymer coatings.

Hot-dip galvanizing delivers long-term, maintenance-free corrosion protection in a variety of exposure conditions. Whether used in atmospheric, concrete, soil, or fresh- or salt-water applications, hot-dip galvanizing delivers maximum service life. There will be no difficult field repairs and no labor and material costs normally associated with replacing unprotected fasteners. Over 90% of all fasteners are made of carbon steel. In general, considering the cost of raw materials, non-ferrous material for the fasteners is generally considered only when a special application is needed.

Carbon steel has excellent workability, offers a broad range of attainable combinations of strength properties, and in comparison with other commonly used fastener materials, is less expensive. The mechanical properties are sensitive to the carbon content. For fasteners, the more common steels are generally classified into three groups. These are namely (i) mild steel, (ii) medium carbon and (iii) alloy steel.

There is no fastener material that is right for every environment. Selecting the right fastener material from the vast array of materials available appears to be a daunting task. Careful consideration may need to be given to strength, temperature, corrosion, vibration, fatigue and many other variables. Most fastener applications are designed to support or transmit some form of externally applied load. If the strength of the fastener is the only concern, there is usually no need to look beyond carbon steel.