ASTM A229 Class I Spring Steel
ASTM A229 class I is ASTM A229 spring steel in the quenched and tempered condition. The graph bars on the material properties cards below compare ASTM A229 class I to: wrought carbon or non-alloy 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
490
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
14 %
Fatigue Strength
710 MPa 100 x 103 psi
Poisson's Ratio
0.29
Shear Modulus
72 GPa 10 x 106 psi
Shear Strength
1020 MPa 150 x 103 psi
Tensile Strength: Ultimate (UTS)
1690 MPa 240 x 103 psi
Tensile Strength: Yield (Proof)
1100 MPa 160 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
400 °C 750 °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
50 W/m-K 29 BTU/h-ft-°F
Thermal Expansion
12 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
1.8 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
1.4 kg CO2/kg material
Embodied Energy
19 MJ/kg 8.0 x 103 BTU/lb
Embodied Water
46 L/kg 5.5 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
200 MJ/m3
Resilience: Unit (Modulus of Resilience)
3260 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
60 points
Strength to Weight: Bending
40 points
Thermal Diffusivity
14 mm2/s
Thermal Shock Resistance
54 points
Alloy Composition
| Fe | 97.5 to 99 | |
| Mn | 0.3 to 1.2 | |
| C | 0.55 to 0.85 | |
| Si | 0.15 to 0.35 | |
| S | 0 to 0.050 | |
| P | 0 to 0.040 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
ASTM A229: Standard Specification for Steel Wire, Oil-Tempered for Mechanical Springs
ASM Specialty Handbook: Carbon and Alloy Steels, J. R. Davis (editor), 1996
Ferrous Materials: Steel and Cast Iron, Hans Berns and Werner Theisen, 2008
Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015