AISI 8740 Steel, oil quenched 830°C (1525°F), 595°C (1100°F) temper, 100 mm (4 in.) round


Subcategory: AISI 8000 Series Steel; Ferrous Metal; Low Alloy Steel; Medium Carbon Steel; Metal

Close Analogs: AISI 8740H

Key Words: DIN 1.6546, UNI 40 NiCrMo 2 KB, B.S. Type 7, ASTM A331, ASTM A505, ASTM A519, MIL-SPEC MIL-S-6049, SAE J404, SAE J412, SAE J770, UNS G87400, AMS 6322, AMS 6323, AMS 6325, AMS 6327, AMS 6358, ASTM A322

Component   Wt. %
C0.38 - 0.43 
Cr0.5 
Fe97 
Component   Wt. %
Mn0.88 
Mo0.25 
Ni0.55 
Component   Wt. %
PMax 0.035 
SMax 0.04 
Si0.23 

Material Notes:
Post oil quenched hardness 42 HRC surface, 37 HRC half-radius, 36 HRC center

Physical PropertiesMetricEnglishComments
Density7.85 g/cc0.284 lb/in³ 

Mechanical Properties
Hardness, Brinell248248 
Hardness, Knoop272272 Converted from Brinell hardness.
Hardness, Rockwell B9898 Converted from Brinell hardness.
Hardness, Rockwell C2323 Converted from Brinell hardness.
Hardness, Vickers261261 Converted from Brinell hardness.
Tensile Strength, Ultimate855 MPa124000 psi 
Tensile Strength, Yield670 MPa97200 psi 
Elongation at Break20.5 %20.5 % in 50 mm
Modulus of Elasticity205 GPa29700 ksi Typical for steel
Bulk Modulus140 GPa20300 ksi Typical for steel.
Poisson's Ratio0.290.29 Calculated
Machinability65 %65 % annealed and cold drawn. Based on 100% machinability for AISI 1212 steel.
Shear Modulus80 GPa11600 ksi Typical for steel

Electrical Properties
Electrical Resistivity2.34e-005 ohm-cm2.34e-005 ohm-cm Typical steel

Thermal Properties
Specific Heat Capacity0.475 J/g-°C0.114 BTU/lb-°F Typical steel
Thermal Conductivity46.6 W/m-K323 BTU-in/hr-ft²-°F Typical steel

References for this datasheet.


Some of the values displayed above may have been converted from their original units and/or rounded in order to display the information in a consistant format. Users requiring more precise data for scientific or engineering calculations can click on the property value to see the original value as well as raw conversions to equivalent units. We advise that you only use the original value or one of its raw conversions in your calculations to minimize rounding error. We also ask that you refer to MatWeb's disclaimer and terms of use regarding this information. MatWeb data and tools provided by MatWeb, LLC.