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 Stainless Steel Bar

S143 Aerospace Stainless Steel Bar

This aerospace-grade precipitation hardening stainless steel combines high mechanical strength with moderate to good corrosion resistance in a variety of media.


The steel is melted in air by an electric process. BS S143 is similar in a number of respects to 17/4 PH stainless steel (UNS S17400 / AISI 630) in its combination of properties. BS S143 stainless steel is supplied in the fully heat-treated condition (solution heat-treated followed by a two-stage precipitation hardening treatment) as bright bar (BS S143D), black bar (BS S143B) and forgings (BS S143C). Material to BS S144 and BS S145 shares a common chemical composition with BS S143. Therefore material to BS S143 can be precipitation hardened using a different sequence of temperatures to produce material meeting the mechanical property requirements of BS S144 or BS S145.


S143 Aerospace Stainless Steel Bar provides useful corrosion resistance in mildly/moderate corrosion environments and is similar to that of basic 300 series stainless steels. The machining and welding of this grade of stainless steel presents no particular problems.

Typical Applications

Commercial applications for this engineering material include:

  • Mechanical components in Aerospace and Defence
  • High-Tech mechanical applications

We stock S143 in flats, round bar and square 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 S143 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.

Interested in this product?
Why not get in touch?


Click Here