Spanners or wrenches

A complete collection of spanners or wrenches is indispensable for the body repair worker. A variety of vehicle body parts,accessories and related parts all utilize common bolt and nut fasteners as well as a range of special fasteners.
The word ‘wrench’ means ‘twist’. A wrench is a tool for twisting or holding bolt heads and nuts. The width of the jaw opening determines the size of the spanner,so that it fits around a nut and a bolt head of equal size. The larger the spanner size, thelonger the spanner:the extra length provides the user with more leverage to turn the larger nut or bolt. Spanners are drop forged and made from chrome mvanadium steels.
Open-ended spanner
This is the most commonly used spanner. However,it has the disadvantage that it fits the nut or bolt on two sides only; consequently there is a greater tendency for the open-ended spanner to slip off the bolt or nut,resulting in rounded nuts and injured hands. Open-ended spanners can be single-ended,or double-ended to fit nuts of consecutive sizes. The head of the spanner is usually set at an angle for use in constricted spaces:when the spanner is turned over,the nut can be approached from a different angle. The openended spanner fits both square head (four-cornered) or hexagonal (hex) head (six-cornered) nuts. These spanners come in sets ranging in AF from 1/4in to 13/8in and in metric from 3.2mm to 42 mm (Figure 3.35).

Ring spanner
The ring spanner is made in a variety of sizes, points and offsets,and may be flat or cranked. Itfits the nut all round by means of teeth cut in theinner surface of the ring. This is a very popular type of spanner as it enables the nut to be tightened quickly and can be used where movement is restricted. The ring spanner is much safer to use as more force can be applied without slipping and rounding the corners of the nut. The handle of the ring spanner can be straight or offset to provide hand clearance. Each end is usually a different size. The ring spanner does have limitations,for there must be sufficient clearance for the jaws to fit over and around the head of the nut or bolt. Ring spanners are available in 6,8 or 12 points. The advantage of the 12-point ring spanner is that it canhold the nut in twelve different positions, which is ideal for working in confined spaces. Ring spanner sets are available in AF1/4 in to 5/4in and metric 6mm to 50mm (Figure 3.36).

Combination spanner
The combination spanner has an open-ended jaw at
one end and a ring on the other end. Both ends are
the same size. The combination is probably the
best choice of second set,for it complements either
open-ended spanner or ring spanner sets. Combin-
ation spanner sets are available in AF1/4 in to5/4 in
and metric 3.2mm to 32mm (Figure 3.37).

Adjustable wrench
An adjustable wrench has one fixed jaw and one movable jaw. The movable jaw is adjusted by means of a worm wheel fitted in the handle,which is meshed with teeth in the jaw. These wrenches are useful because they are manufactured in a range of sizes and each one can be adjusted to fit many sizes of nuts (Figure 3.38).