The name of these washers comes from their bowl shape. This product range is distinguished by the fact that it offers 4 different shapes: the STB 20-3 series and the STB 20-4 series are rather conical while the STB 20-2 and STB 20-5 series are wider. These cup washers are essential items as they improve the aesthetic appearance of a fastener.
The 4 shapes of cup washers are an asset since this allows to adapt to all needs. They are all offered as standard in black nylon and white nylon.
These washers protect surfaces and provide good electrical insulation and absorb shocks and vibrations.
Our range of nylon finishing washers, ideally suited to hide countersunk screw heads and ensure a neat finish to applications. The 20-4 series are end caps for use with pan head screws.