bolttype

Bolttype is a term used in mechanical engineering and fastener procurement to describe a bolt category defined by design features and intended use. A bolttype specification typically includes head style, drive method, thread form, length, shank type, material grade, and surface coating. The bolttype label helps engineers communicate requirements and ensures compatibility with nuts, washers, and mating components.

Common bolttype features include head styles such as hex head, socket cap, button head, flange, carriage, eye, and shoulder bolts; drive methods such as hex drive, internal hex, Torx, or slotted; thread forms such as coarse or fine; and shank types such as fully threaded or partially threaded. Bolttypes are selected to meet strength, stiffness, and assembly constraints.

Materials and coatings: bolts are made from carbon steel, alloy steel, stainless steel, aluminum, or titanium, often with coatings such as zinc plating, galvanization, chromate, or black oxide to improve corrosion resistance or wear.

Standards and manufacturing: bolttype choices align with standards from ISO, ANSI/ASME, JIS, and others (for example ISO 4014/4017, ANSI/ASME B18.2.1, ASTM A325). Manufacturing typically involves hot or cold forging, cold heading, and thread rolling, followed by heat treatment and surface finishing.

Applications and considerations: bolttype is selected based on load, environment, mating parts, lubrication, and installation method. Proper torque, preload, and thread engagement are essential for performance and safety.

See also: fastener, bolt, screw, nut, thread, preload.