MakeItFrom.com
Menu (ESC)

ASTM A369 Grade FP21 vs. SAE-AISI 4340M Steel

Both ASTM A369 grade FP21 and SAE-AISI 4340M steel are iron alloys. Both are furnished in the annealed condition. They have a very high 96% of their average alloy composition in common. There are 32 material properties with values for both materials. Properties with values for just one material (3, in this case) are not shown.

For each property being compared, the top bar is ASTM A369 grade FP21 and the bottom bar is SAE-AISI 4340M steel.

Metric UnitsUS Customary Units

Mechanical Properties

Brinell Hardness 140
710
Elastic (Young's, Tensile) Modulus, GPa 190
190
Elongation at Break, % 20
6.0
Fatigue Strength, MPa 160
690
Poisson's Ratio 0.29
0.29
Shear Modulus, GPa 74
72
Shear Strength, MPa 300
1360
Tensile Strength: Ultimate (UTS), MPa 470
2340
Tensile Strength: Yield (Proof), MPa 240
1240

Thermal Properties

Latent Heat of Fusion, J/g 260
280
Maximum Temperature: Mechanical, °C 470
430
Melting Completion (Liquidus), °C 1470
1440
Melting Onset (Solidus), °C 1430
1400
Specific Heat Capacity, J/kg-K 470
480
Thermal Conductivity, W/m-K 41
38
Thermal Expansion, µm/m-K 13
13

Electrical Properties

Electrical Conductivity: Equal Volume, % IACS 7.7
7.8
Electrical Conductivity: Equal Weight (Specific), % IACS 8.8
9.1

Otherwise Unclassified Properties

Base Metal Price, % relative 4.0
3.9
Density, g/cm3 7.8
7.8
Embodied Carbon, kg CO2/kg material 1.8
1.9
Embodied Energy, MJ/kg 23
26
Embodied Water, L/kg 61
55

Common Calculations

PREN (Pitting Resistance) 6.2
2.2
Resilience: Ultimate (Unit Rupture Work), MJ/m3 80
120
Resilience: Unit (Modulus of Resilience), kJ/m3 150
4120
Stiffness to Weight: Axial, points 13
13
Stiffness to Weight: Bending, points 24
25
Strength to Weight: Axial, points 17
84
Strength to Weight: Bending, points 17
51
Thermal Diffusivity, mm2/s 11
10
Thermal Shock Resistance, points 14
70

Alloy Composition

Carbon (C), % 0.050 to 0.15
0.38 to 0.43
Chromium (Cr), % 2.7 to 3.4
0.7 to 1.0
Iron (Fe), % 94.3 to 96.2
93.3 to 94.8
Manganese (Mn), % 0.3 to 0.6
0.65 to 0.9
Molybdenum (Mo), % 0.8 to 1.1
0.35 to 0.45
Nickel (Ni), % 0
1.7 to 2.0
Phosphorus (P), % 0 to 0.025
0 to 0.012
Silicon (Si), % 0 to 0.5
1.5 to 1.8
Sulfur (S), % 0 to 0.025
0 to 0.012
Vanadium (V), % 0
0.050 to 0.1