Washers without chamfer DIN 125-1-A / ISO 7089-polyamide 21

Plastics differ from polymers due to the addition of additives. Typical additives include plasticisers, stabilisers, colourants, fillers and reinforcing agents. Plastics can be classified according to various criteria, e.g. molecular synthesis, molecular structure, chemical origin or, based on their mechanical and thermal behaviour, into the three main groups: thermoplastics, thermosets and elastomers.

Polyamide 6.6 is a thermoplastic and therefore has long, thread-like macromolecules that have no cross-linking points. PA 6.6 is milky white, has a smooth and abrasion-resistant surface, is resistant to chemicals and solvents and is hard and tough. Various standards, such as DIN EN 34810, DIN 34811, DIN 34812, DIN 34813, DIN 34814, DIN 34815 and DIN 34816, regulate the properties of mechanical fasteners made of plastics (screws, nuts, washers).