Stainless Steel BS S143 Round Bars / Aerospace BS S143 Rods / BS S143 Rings

Product Description

BS S143 Stainless Steel (Aerospace Series)

BS S143 is a high-strength, corrosion-resisting chromium-nickel-copper-niobium precipitation-hardening steel. It is typically supplied in the precipitate hardened (aged) condition and is widely utilized in the aerospace industry for its excellent mechanical properties and moderate corrosion resistance.

Technical Specifications & Equivalents

BS S143 is often referred to as the aerospace equivalent of 17-4 PH stainless steel. While the chemistries are virtually identical, the "S" series designation ensures the material has undergone the rigorous testing and quality control required for flight-critical components.

Mechanical Properties (Typical)

The material is favored for its high tensile strength and proof stress, maintaining stability at temperatures up to 300°C.

• Tensile Strength ($R_m$): 930–1080 MPa

• 0.2% Proof Stress ($R_{p0.2}$):$\ge$ 785 MPa

• Elongation ($A$):$\ge$ 16%

• Hardness: 277–341 HBW

Product Forms & Applications

1. Round Bars & Rods

Standard diameters usually range from 12.7mm (1/2") to 250mm, often centerless ground or smooth turned.

• Use Cases: Fasteners, gears, engine components, and hydraulic actuators.

2. Rings & Forgings

Rings are typically produced via seamless rolled ring forging to ensure superior grain flow and structural integrity.

• Use Cases: Bearing races, flange assemblies, and turbine housing seals.

Key Performance Characteristics

• Corrosion Resistance: Comparable to 304 stainless steel in most environments. It resists atmospheric corrosion and many organic chemicals.

• Weldability: Highly weldable using common methods like TIG or MIG. Unlike many high-strength steels, it generally does not require pre-heating.

• Machinability: Best machined in the solution-annealed condition, though it can be finished in the S143 (hardened) state using carbide tooling and slower speeds.

Supply Condition

The material is almost exclusively supplied as S143D (drawn) or S143B (hot rolled/forged), followed by the hardening heat treatment to achieve the required mechanical values. If you require the material in a softer, more formable state for complex machining, you may look for BS S144 (the solution-treated version of the same alloy).