Wire drawing

The steel wire is coated with DECORRDAL zinc phosphate and HAKUFORM lubricants in first- and second-pass wire drawing. In some applications, the conversion layer can be omitted when special HAKUFORM high-performance lubricants are used. Similar processes are available for stainless steel or aluminum. Due to work hardening, the wire must be annealed after a few drawing operations (after stripping with HAKUPUR and/or DECORRDAL, if applicable). A new coating is applied before the next drawing process. HAKUFORM forming lubricant is used for a final bright drawing with only a small reduction in cross section. For smaller wire diameters using fine and scraper drawing, e.g., steel cord, HAKUFORM lubricants are used exclusively as well.

Cold heading

Coated and potentially pre-drawn wire is used for the cold heading of fasteners and for increasingly sophisticated, smaller drawing parts for which the wire is either coated in the wire factory or by the fastener manufacturer (standard: DECORRDAL conversion layer + HAKUFORM or HAKUDRAW lubricant, in some cases without conversion layer). Immediately after a calibration drawing, the coated wire is sheared to length and formed in multistage horizontal presses. HAKUFORM cold extrusion oils are used as additional lubrication and for cooling in these bolt makers.