Types of Fastener

The nuts and bolts holding our cars together are known as fasteners. The Wikipedia definition is "A fastener is a hardware device that mechanically joins or affixes two or more objects together. In general, fasteners are used to create non-permanent joints; that is, joints that can be removed or dismantled without damaging the joining components".

 There are many types. According to the Standard-Triumph Hardware Catalogue they are as follows:

TYPE	IMAGE
BOLTS - Hexagon Head These do not have threads which go right up to the head and normally have flat ends.
SETSCREWS - Hex Head These are similar to the bolts (above) but have threads which do go right up to the head.
CARRIAGE BOLTS These have domes tops and a square or ribbed shank under the head. They are used in slots where a square shank would locate the bolt in position.
PIPE CLIPS The 'Supergrip' (bottom) is original equipment for radiator hoses, and are frequently replaced by Jubilees (right).
HEXAGON NUTS These go onto similarly threaded bolts or screws.
HEXAGON JAM NUTS These are sometimes called half nuts and are used when two need to be 'locked' together.
SQUARE NUTS Compared to hex nuts, square nuts have a greater surface in contact with the part being fastened, and therefore provide greater resistance to loosening.
HEX NUT SLOTTED / CASTLE NATIONAL THREAD These similar nuts are used when they need to be locked by a split pin as on wheel hubs.
PHILIDAS NUTS These are used when locking is required in any position. The originating UK company is still trading!
NYLOC NUTS These are 'self locking' nuts. Normally single use only. No longer called 'Simmonds" although like Philidas the company still exists.
SCREW-COUNTERSUNK These are used for trim fixing e.g. the rear deck of the GT6