QuikDrive® Drywall screws Coarse thread St pho sw 3.9x40

Steel is an iron-carbon alloy with a maximum carbon content of 2% by mass. The steels achieve their intended physical and mechanical properties through various hardening, annealing and tempering processes. It is also possible to harden the edge zone by surface hardening, case hardening or nitriding. Well-known steel grades are structural steels, free-machining steels, case-hardening steels, nitriding steels, tempering steels, tool steels and stainless steels.

Phosphating is carried out in accordance with DIN EN ISO 9717. If no specific corrosion testing procedure has been agreed between the customer and the supplier, the neutral salt spray test in accordance with ISO 9227 is used. It should be noted in this context that untreated phosphate coatings do not provide corrosion protection – consequently, a post-treatment with sealants, greases, oils or wax is usually carried out.