Punching into raw shape
- cutting to length
- head pre-shaping
- final shaping with AW-drive and label
Pinching of the screw tip
- no cutting process
- ASSY Plus tip for wood screws
- Pias-tip for sheet metal drilling screws
Rolling on the thread
no cutting process when rolling on the thread
The first and foremost used procedures in the production process of a screw are heat treatment processes for case hardening, tempering and annealing. The structure of the alloy is converted to ensure the required mechanical features.
Depending on the carbon content the screw is heated up to a certain temperature which is kept for an extended period of time. Thereby the microstructure is converted and an increase of hardness is achieved through a subsequent quenching in oil.
The now glass-hard (brittle) screw cannot be used in the field yet. In a second process called annealing it is heated up once more. During this process the high hardness decreases and the tenacity improves considerably.
- Zinc coating for corrosion protection
- Layer thickness 5µ-12μ
- Example: blue cremated or yellow zinc coated