AISI 8740 Steel, annealed 815°C (1500°F)


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 

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

Mechanical Properties
Hardness, Brinell201201 
Hardness, Knoop223223 Converted from Brinell hardness.
Hardness, Rockwell B9393 Converted from Brinell hardness.
Hardness, Rockwell C1313 Converted from Brinell hardness. Value below normal HRC range, for comparison only.
Hardness, Vickers211211 Converted from Brinell hardness.
Tensile Strength, Ultimate695 MPa101000 psi 
Tensile Strength, Yield415 MPa60200 psi 
Elongation at Break22.2 %22.2 % in 50 mm
Modulus of Elasticity205 GPa29700 ksi Typical for steel
Bulk Modulus140 GPa20300 ksi Typical for steel.
Poisson's Ratio0.290.29 Calculated
Izod Impact41 J30.2 ft-lb 
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.


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