Hardware, Oils and consumables
WASHERS
Prefix:
WP = plain
WS = spring
WC = copper
WA = aluminium
WF = fibre
WD = dowty
WT = thackery
WW = wave washer
In this series, the first number indicates the measuring units 1 = English, 2 = metric. The second and third numbers are the internal diameter in 1/16'' of an inch or 1mm. The forth and fifth numbers are the outside diameter in 1/16th of an inch or 1mm. The sixth, seventh, and eighth numbers are the thickness in 0.001'' or 0.01mm. A number in the 9th column indicates a special finish. In the case of spring washers, 1 in the ninth column indicates shakeproof star internal, 2 is shakeproof star external, and 3 is a shake proof spring type.