Stainless Steel, Martensitic1.4021 (420) Bar

A martensitic machining bar with machinability enhanced through the addition of sulphur.

As with most other free-machining stainless steels the improvement in machinability is achieved by addition of sulphur which forms manganese sulphide inclusions; this sulphur addition also lowers the corrosion resistance, weldability and formability to below that of its non-free machining equivalent Grade 410.

Martensitic stainless steels are optimised for high hardness, and other properties are to some degree compromised. Fabrication must be by methods that allow for poor weldability and usually also allow for a final harden and temper heat treatment. Corrosion resistance is lower than the common austenitic grades, and their useful operating temperature range is limited by their loss of ductility at sub-zero temperatures and loss of strength by over-tempering at elevated temperatures.

Range Enquiry

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Related Specifications

1.4021 is similar, but may not be a direct equivalent to:

420
UNS42000
1.4021, 1.4024, 1.4028, 1.4029, 1.4030, 1.4034

Properties

Chemical Composition

Chemical Element	% Present
Carbon (C)	0.16 - 0.25
Chromium (Cr)	12.00 - 14.00
Manganese (Mn)	0.00 - 1.50
Silicon (Si)	0.00 - 1.00
Phosphorous (P)	0.00 - 0.04
Sulphur (S)	0.00 - 0.03
Iron (Fe)	Balance

Mechanical Property	Value
Proof Stress	500 - 600 MPa
Tensile Strength	700 - 950 MPa
Elongation A	12 - 13 %

General Physical Properties

Physical Property	Value
Density	7.75 g/cm³
Thermal Expansion	10.3 x 10^-6/K
Modulus of Elasticity	200 GPa
Thermal Conductivity	24.9 W/m.K
Electrical Resistivity	0.55 x 10^-6 Ω .m

Applications

Valve parts
Pump shafts
Automatic screw machined parts
Motor shafts
Washing machine components
Bolts and nuts
Studs
Gears
Shear blades
Cutlery (blades)
Surgical instruments

Characteristics

Good corrosion resistance similar to 410 plus increased strength and hardness
It is magnetic in both the annealed and hardened conditions
Maximum corrosion resistance is attained only in the fully hardened condition
It is never used in the annealed condition

Additional Information

Weldability

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Disclaimer

This Data is indicative only and as such is not to be relied upon in place of the full specification. In particular, mechanical property requirements vary widely with temper, product and product dimensions. All information is based on our present knowledge and is given in good faith. No liability will be accepted by the Company in respect of any action taken by any third party in reliance thereon. Please note that the 'Datasheet Update' date shown above is no guarantee of accuracy or whether the datasheet is up to date.

The information provided in this datasheet has been drawn from various recognised sources, including EN Standards, recognised industry references (printed S online) and manufacturers' data. No guarantee is given that the information is from the latest issue of those sources or about the accuracy of those sources. Material supplied by the Company may vary significantly from this data but will conform to all relevant and applicable standards. As the products detailed may be used for a wide variety of purposes and as the Company has no control over their use; the Company specifically excludes all conditions or warranties expressed or implied by statute or otherwise as to dimensions, properties and/or fitness for any particular purpose, whether expressed or implied. Advice given by the Company to any third party is given for that party's assistance only and without liability on the part of the Company. All transactions are subject to the Company's current Conditions of Sale. The extent of the Company's liabilities to any customer is clearly set out in those Conditions; a copy of which is available on request.