Equivalent Specifications
BS970 – 1955 EN24
DIN 34CrNiMo6
W.Nr. 1.6582
AISI 4340
Key Features
817M40 is a 1.5% Ni-Cr-Mo high hardenability, high tensile strength steel.
Typical Uses
This alloy is used in most industry sectors for a wide variety of applications including high strength machine parts, collets, spindles, gears, bolts shafts and couplings etc.
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817M40
It is generally supplied in the Hardened and Tempered condition in the tensile range of 850 – 1000Mpa (T Condition)
but can be heat treated to 850 – 1550Mpa dependent on section size (T – Z Condition). It could also be supplied in the
annealed condition suitable for pre-heat treatment machining.
This grade is very popular and widely used for many high strength applications where a good combination of strength
and impact properties are essential in fairly large components.
Description |
High Tensile Steel |
Nominal Composition |
1.5% Ni-Cr-Mo Steel |
Alloy Type |
Cast |
Typical Mechanical Properties
Tensile Strength (N/mm²) |
850 |
Proof/Yield Strength (N/mm²) |
635 |
Elongation (%) |
13 |
Hardness Brinell |
248 |
Impact Izod J20°C |
35 |
Typical Physical Properties
Density g/cm³ |
7.85 |
Melting Temperature Range °C |
1370-1510 |
Thermal Conductivity W/mK |
45 |
Electrical Resistivity μΩ.m15°C |
2.48 |
Coefficient of Thermal Expansion 0-250°C |
13.1 |
Relative Magnetic Permeability |
2.05 |
Coefficient of Friction |
0.2 |
This Data is indicative only and must not be seen as a substitute for the full specification from which it is drawn. In particular, the mechanical property requirements vary widely with tempeter, product and product dimensions. The information is based on our present knowledge and is given in good faith. However, no liability will be acepted by the Company in respect of any action taken by any third party in reliance thereon.
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.
Any 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. Any contract between the Company and a customer will be subject to the Company's 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.