Grade 431 (1.4057) is the “all round” engineering martensitic stainless steel, combining fair corrosion resistance with good strength and impact toughness.
Approximate Composition – 15% Cr 2% Ni (Exact composition ranges vary between EN and ASTM standards). “Old” BS 970 431S29 still used for its higher Ni content.
This grade combines the following characteristics:
• Fair corrosion resistance (better than 420)
• High hardness and strength
• Wear resistance
• Controlled balance of mechanical properties by hardening and tempering
• Improved toughness compared to 420 due to lower carbon and nickel addition
• Not easy to weld
431 has one of the best combinations of corrosion resistance, high strength and good impact toughness of all the stainless steels. This accounts for its popularity in a wide range of engineering applications which include:
Drive shafts, propeller shafts, bearings, gears, hydraulic rams, valve stems, actuators, satellite parts, conveyor drive systems, hi-fi equipment stands, packaging machinery, crane pins, seat dampers for boats, mixing blades, golf clubs.
431 offers a cost-effective solution in many challenging engineering applications.