SWCH8A is a commonly used carbon steel wire for cold heading. In terms of chemical composition, it contains a specific proportion of carbon, manganese and other elements. The precise control of its composition helps to achieve stable performance; it has good strength and toughness. After proper cold working, it can meet the needs of manufacturing various high-strength parts; it has good plastic deformation ability in cold heading performance, and it is not easy to have defects such as cracks during cold heading. At the same time, the surface quality is usually good, smooth and clean, which helps to reduce the subsequent processing steps and costs.

The "8" in SWCH8A represents the middle value of carbon content in steel, and A represents aluminum-killed steel.

Chemical element content (%)

Specification：2.00~42.00mm

Production process:

Process D: cold drawing of wire rod into steel wire;
Process DA: annealed cold drawn steel wire and annealed wire rod into cold drawn steel wire.

Application：It is mainly used to manufacture various fasteners such as bolts, nuts, screws, etc, it can also be used to manufacture cold extruded parts and various cold heading parts, and is widely used in automobiles, electrical appliances, cameras, textile equipment, electronic equipment, machinery manufacturing and other fields.

Mechanical properties:

-Before cold working, the wire is spheroidized annealed (DA) with a tensile strength of ≥290MPa, a cross-sectional shrinkage of ≥55%, and a hardness of ≤80HRB;

-After cold working (D) of wires with a diameter of not more than 3mm, the tensile strength is ≥540MPa;

-After cold working (D) of wires with a diameter of more than 3mm and not more than 4mm, the tensile strength is ≥440MPa, and the cross-sectional shrinkage is ≥45%;

-After cold working (D) of wires with a diameter of more than 4mm and not more than 5mm, the tensile strength is ≥390MPa, and the cross-sectional shrinkage is ≥45%;

-After cold working (D) of wires with a diameter of more than 5mm, the tensile strength is ≥340MPa, the cross-sectional shrinkage is ≥45%, and the hardness is ≤85HRB.

It should be noted that for steel wire with a diameter of 20mm or more, the minimum cross-sectional reduction rate should be 5 less than the specified value; for steel wire with a diameter of 3mm or less, the cross-sectional reduction rate is generally not specified.