Bolts have been defined as headed fasteners having external threads that meet an exacting, uniform bolt thread specification (such as ISO metric screw thread M, MJ, Unified Thread Standard UN, UNR, and UNJ) such that they can accept a non-tapered nut. Screws are then defined as headed, externally threaded fasteners that do not meet the above definition of bolts. [ citation needed ] These definitions of screw and bolt eliminate the ambiguity of the Machinery's handbook distinction. And it is for that reason, perhaps, that some people favor them. However, they are neither compliant with common usage of the two words nor are they compliant with formal specifications.
Mating fasteners are known by many different names: sex bolt, binding posts, Chicago screws, interscrews, barrel bolts, barrel nut, partition screws, door closure bolts, furniture screws, panel fasteners, architectural sex bolts, arch series screws, hinge screws, display fasteners, screw nuts, connector bolts, threaded rivets, grommet nuts, post and screw sets, book screws, and stationary screws. Applications vary widely from book binding to installing bathroom partitions. This group of fasteners are used to assemble fitness apparatus, solar panels, playground equipment, railing systems, furniture, athletic helmets, knives, store fixtures, signs, panic bars, and many other products.