+44 (0) 114 244 0527

CS4 Mild Steel

About CS4 Mild Steel

CS4 is a cold rolled mild steel traditionally used for cold forming. Cold-rolled steel is about 20% stronger than hot-rolled steel through the use of strength hardening. Cold-rolled steel can be furhter heat-treated by the customer.

It is a soft steel with a high ductility level and a low carbon content. 

Whilst the advent of newer steels have largely replaced CS4 for a lot of manufacture, it still has benefits where a close thickness tolerance is required or where stiffness is an advantage.

 BSS hold a range of CS4 in the full hard rolled condition, with a hardness of 165VPN and tensile strength Rm of 540N/mm². 

CS4 is part of BS1449.

Typical Applications

CS4 is utilised in standard fabrication and engineering.

It is typically used for the manufacture of shims and washers.

In addition to supplying CS4 in sheet for shim manufacture, BSS can supply laser cut shims – call 0114 244 0527 with your requirements. 

International Equivalents

DIN 1624BS 1449En10139%C%Mn%Si%S
St4CS1DC04.03 – .06.18 – .40.02 max.02 max
St4/RRSt3CS1/CS3 .04 – .08.40 max.03 max.02 max
St2CS4DC01.08 – .13.30 – .40.03 max.03 max
 .14 – .17.60 – .80.15 – .25.02 max


Our range

BSS stock CS4 fully hard rolled from .05mm (.0015″ or 48swg) through to 1.63mm (0.064″ or 16 swg).

We do not supply Mill Certificates with orders, we only supply Certificates of Conformity.

Please contact us on 0114 244 0527 (option 2) to make an enquiry.