SAE-AISI 51B60 (G51601) Boron Steel
SAE-AISI 51B60 steel is an alloy steel formulated for primary forming into wrought products. 51B60 is the designation in both the SAE and AISI systems for this material. G51601 is the UNS number.
The properties of SAE-AISI 51B60 steel include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare SAE-AISI 51B60 steel to: SAE-AISI wrought steels (top), all iron alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Brinell Hardness
200
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
12 to 21 %
Fatigue Strength
280 to 340 MPa 40 to 50 x 103 psi
Poisson's Ratio
0.29
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
390 to 420 MPa 57 to 60 x 103 psi
Tensile Strength: Ultimate (UTS)
660 MPa 95 to 96 x 103 psi
Tensile Strength: Yield (Proof)
400 to 550 MPa 58 to 80 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
420 °C 780 °F
Melting Completion (Liquidus)
1450 °C 2650 °F
Melting Onset (Solidus)
1410 °C 2570 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
43 W/m-K 25 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.2 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.3 % IACS
Otherwise Unclassified Properties
Base Metal Price
2.1 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
1.4 kg CO2/kg material
Embodied Energy
19 MJ/kg 8.3 x 103 BTU/lb
Embodied Water
49 L/kg 5.9 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
73 to 120 MJ/m3
Resilience: Unit (Modulus of Resilience)
420 to 800 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
23 points
Strength to Weight: Bending
22 points
Thermal Diffusivity
12 mm2/s
Thermal Shock Resistance
19 points
Alloy Composition
Among alloy steels, the composition of SAE-AISI 51B60 steel is notable for including boron (B). Boron is used to improve hardenability. It has a substantial effect when added in even tiny amounts.
| Fe | 97 to 97.8 | |
| Mn | 0.75 to 1.0 | |
| Cr | 0.7 to 0.9 | |
| C | 0.56 to 0.64 | |
| Si | 0.15 to 0.35 | |
| S | 0 to 0.040 | |
| P | 0 to 0.035 | |
| B | 0.00050 to 0.0030 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM A752: Standard Specification for General Requirements for Wire Rods and Coarse Round Wire, Alloy Steel
Boron in Steel, S. K. Banerji and J. E. Morral (editors), 1980
ASTM A29: Standard Specification for Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements for
ASM Specialty Handbook: Carbon and Alloy Steels, J. R. Davis (editor), 1996
Manufacture and Uses of Alloy Steels, Henry D. Hibbard, 2005
Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015