Hexagon nuts DIN 555-polyamide 6.6 M3

The wrench sizes for hexagon bolts and nuts are specified in ISO 272: 1982-01. The nominal wrench size on the workpiece (e.g. bolt, nut) is the same as that on the tool. However, there is some play between the two to allow the tool to be fitted without difficulty. The relationship between the nominal diameter d of the thread and the wrench size s is standardised in EN ISO 4014 and EN ISO 4017 for hexagon bolts, and in EN ISO 4032 for hexagon nuts (dimensions in mm).

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).