Cold heading

Cold heading makes it possible to obtain mechanical parts from the wire rod using plastic deformation on multi station presses making it possible to produce screws, bolts, nuts, spacers, pivots, rivets, fasteners and other special components according to design. A group of steels with structural morphology and reduced hardening factors, designed and produced to guarantee increased deformability so as to reduce forming and cutting machine tool wear to a minimum.

Designations

Valbruna Grade Steel type W.N. AISI UNS EN BS
AISR Cold Heading 1.4301/1.4307 304/304L S30400/S30403 X5CrNi18-10/X2CrNi18-9 304S15/304S31
AISRU Cold Heading 1.4567 304CU S30430 X3CrNiCu18-9-4 -
AISRU/1 Cold Heading 1.4567 - S30430 X3CrNiCu18-9-4 394S17
AISRU/2 Cold Heading - 304CU S30430 - 394S17
AISRUB Cold Heading 1.4560 - - X3CrNiCu19-9-2 -
AISRUH Cold Heading 1.4567 304CU S30430 X3CrNiCu18-9-4 394S17
APMR Cold Heading 1.4401 / 1.4404 316 / 316L S31600 / S31603 X2CrNiMo17-12-2 / X5CrNiMo17-12-2 316S14 / 316S19
APMRU Cold Heading 1.4578 316CU - X3CrNiCuMo17-11-3-2 396S17
AN5 Corrosion Resistant Alloys 1.4980 - S66286 - 286S31

Cold Drawing

This process involves drawing the material through a precision die which defines the bar into precise dimensional and geometrical tolerances. Cold Draw tolerances are much more precise than that of hot rolled materials. Additionally, the post drawn surface is much smoother.

Cold drawing generates work hardening which increases strength by changing the structural morphology in a more or less marked manner, depending on the type of steel, the steels work-hardening rate and the percentage change of the cross sectional area of the material by the cold drawing process. The cold drawing operation can be carried out by coil to bar, coil-to-coil or from bar-to-bar. In general, except for few exceptions, all stainless steels can be drawn to some extent. Factors for successful drawing include the right choice of die angles, proper lubrication and the condition of the material. Particular care must be exercised when drawing re-sulfurized steels and those with a high transition temperature.