hexagonal wrench
51Spark plug — A spark plug (also, very rarely nowadays, in British English: a sparking plug) is an electrical device that fits into the cylinder head of some internal combustion engines and ignites compressed aerosol gasoline by means of an electric spark.… …
52Bicycle lock — A bicycle lock is a physical security device used on a bicycle to prevent theft. It is generally used to fasten the bicycle to a bicycle stand or other immovable object.An important difficulty in preventing the theft of a bicycle is that the… …
53British Standard Whitworth — (BSW) is one of a number of imperial unit based screw thread standards which use the same bolt heads and nut hexagonal sizes, some others being British Standard Fine thread (BSF) and British Standard Cycle. These three are collectively called… …
54Benzene — For other uses, see Benzene (disambiguation). See also: Benzole Benzene …
55lag screw — a heavy wood screw having a square or hexagonal head driven by a wrench. Also called coach screw, lag bolt. See illus. under screw. [1870 75] * * * …
56machine bolt — a threaded fastener, used with a nut for connecting metal parts, having a thread diameter of about 1/4 in. (6.4 mm) or more and a square or hexagonal head for tightening by a wrench. Cf. cap screw, machine screw, stove bolt. See illus. under… …
57Allen screw — noun A screw whose head has a hexagonal socket. See Also: Allen bolt, Allen key, Allen wrench …
58hex head bolt — noun A bolt with a hexagonal head. See Also: hex head screw, wrench …
59Allen bolt — noun A bolt whose head has a hexagonal socket. See Also: Allen key, Allen screw, Allen wrench …
60Allen — masc. proper name, variant of ALAN (Cf. Alan) (q.v.). In reference to wrench, key, screw, etc. with hexagonal socket or head, 1913, from the Allen Manufacturing Company of Hartford, Connecticut, U.S …
