About Smiths

We are a world-class supplier of engineering raw materials. Our objective is to provide all our customers, from the small machine shop to the large multi-national corporation, a supply path that continuously delivers the highest levels of service, quality and value.


Aerospace Steel Bar

S156 Aerospace Steel Bar

BS S156 in the British Standard Aerospace Series is a 4% Ni-Cr-Mo case-hardening steel with a tensile strength of 1,320-1,520 MPa.

Delivery Condition

The material is manufactured by consumable electrode vacuum arc remelting (VAR). Bars, and where practicable, forgings, are subjected to ultrasonic examination. Bars and forgings are supplied in the normalised and softened condition. Parts produced from bar and forgings are required to be supplied in the finally heat treated condition which consists of carburising, hardening and tempering.


BS S156 aerospace steel bar is supplied in black bar, bright bar and forgings. The supply condition of the alloy is normalised and softened. In fabrication, parts produced will need to be supplied in the heat treated condition - this consists of carburising, hardening and tempering.

Typical Applications

Commercial applications for this engineering material include:

  • High performance components for Autosport
  • Aircraft engineering components

We stock S156 in round bar.

Technical Assistance

Our knowledgeable staff and resident metallurgists will be pleased to assist you further on any technical topic. Smiths Metal Centres Limited also boasts an in-house UKAS Accredited Testing Laboratory which is unique within the multi-metal and plastic stockholding sector. We believe this underlines our total commitment to quality and our ethos of being the complete service provider.

Additional Info

A technical datasheet for S156 is available in PDF file format. To view and download, please click here.

We offer in-house processing options - for more information, please refer to our processing services.

Read our corporate brochure by clicking here.

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