1. Standardization

Given their importance in mechanical engineering, threaded fasteners (screws, studs, nuts) are covered by a large number of standards. We will only consider the case of metric-sized elements, and will refer to the most general standards: French standards (NF), European standards (NF EN), international standards (NF EN ISO) .

In particular, these recommendations concern materials, test specifications, dimensions and tolerances, mechanical characteristics and clamping tools.

Among these standards, those relating to the dimensional and mechanical specifications of general-purpose fasteners NF E 27-005 and 009, NF EN ISO 898-1...