Aircraft Stainless Steel BS S145 / 3S145 (FV 520)

Technical Data Sheet


Chemical Composition Limits
Weight% C Si Mn P + S max Cr Cu Mo Nb Ni
S145 0.07 0.6 1.0 P 0.035
S 0.025
13.2-14.7 1.20-2.0 1.20-2.0 0.10-0.40 5.0-5.80

S145 is a British aerospace grade, precipitation hardenable stainless steel which combines high mechanical strength with moderate corrosion resistance. It is widely used for mechanical components in aerospace and defense applications as well as other high-tech mechanical applications. It is chemically identical to BS S143 and BS S145 and is supplied as bright bar, usually in one of two heat treatments: Solution Treated, designated S145D, or Solution Treatedand Precipitated, designated S145H. The heat treatment is as follows:

Solution Treatment : 850-950°C/1hr plus air cool (S145D)
Precipitation: 440-460°C / 30mins plus air cool (S145D)

Typical Mechanical Properties

Grade Condition Tensile Strength N/mm² Yield Strength N/mm² Elongation (%) Hardness (HB) Ruling Section
S145D Solution Treated S145D - - - 363 max -
S145H Solution Treated & Precipitated S145H 1270-1470 1030 15 352-401 <75mm
S145H Solution Treated & Precipitated S145H 1270-1470 1030 10 352-401 >75mm

Alloy S145 is available in Bars and Forgings. For all stock availability contact Sales.


BS S143
BS S144
Def Stan 95-14

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Every effort is made to ensure that technical specifications are accurate. However, technical specifications included herein should be used as a guideline only. All specifications are subject to change without notice.