Steels:
- carbon steel C15E - 1.1141 EN 10084
- carbon steel C45 - 1.0503 EN 10083-2

Stainless steels
- Stainless steel A2-AISI 304 1.4301 EN 10088-1
- Stainless steel A4 1.4401 EN 10088-1

The C45 and the Stainless Steel A2 were chosen because in addition to their natural qualities as good construction materials, they give very good surface hardness and finish on the thread side after the rolling. A4 stainless steel has also an excellent corrosion resistance.
C 15 is an excellent quality-price compromise.
After rolling, C15 has a surface hardness of approximately 160/180 HB. C45 of approximately 250 HB, A2 stainless steel of approximately 260 HB and A4 stainless steel of approximately 280 HB while roughness is less than 1 m Ra

These two features are decisive factors for qualitative appraisal of trapezoidal screws because they give very small friction coefficients, much lower than those obtainable with machined screws where other conditions (such as speed, load and lubrication) are equal.

Because of the low friction coefficient the amount of heat generated during movement is limited with a smaller nut heating. Nut life also increases. We make nuts with 10 kinds of material so to better meet the different needs.