Process used to give the screw the hardness and toughness necessary to screw or drill into the various materials.
It is a thermochemical process, carried out in sophisticated casehardening furnaces, which is carried out in two phases:

When specific gases are injected in a controlled atmosphere at a high temperature, an enriched carbide and nitride coating is obtained on the screw (surface hardness).

The screw is cooled abruptly to increase the toughness and resilience of the metal, together with an extremely hard surface: characteristics necessary to be able to withstand high torque and create thread in the hardest materials (core hardness).

The carbonitriding process is subject to the SPC (Statistical Product Control) system, which guarantees a constantly high level of quality in time.
Traceability is ensured by the batch number printed on every label.