| Mechanical Property | 1018 | 4130 | 4140 | 1045 | 1215 | 4340 |
| Tensile Strength, Yield (MPa) | 310 | 460 | 655 | 450 | 415 | 470 |
| Shear Modulus (GPa) | 78 | 80 | 80 | 60 | 80 | 74 |
| Elongation at Break (%) | 20 | 21.5 | 25.7 | 12 | 10 | 22 |
| Hardness (Brinell) | 131 | 217 | 197 | 170 | 167 | 217 |
| Density (g/cm3) | 7.87 | 7.85 | 7.85 | 7.87 | 7.87 | 7.85 |
| Advantages | Excellent weldability Well suited to surface hardening processes |
Exceptionally tough Easy to heat-treat Highly workable |
High fatigue strength Resistance to abrasion and impact Good machinability in the annealed condition |
Good weldability High machinability High strength and hardness |
Free machining steel High sulfur content |
High strength Great toughness and strength |
| Applications | Spindles, rods, shafts, pins, and mold components. | Drills, taps, and aircraft engine mountings. | Spindles, bolts, nuts, couplings, and automotive parts. | Forged connecting rods, axles, bolts, light gears | Hose fittings, screws, couplings, studs, and pins. | Shafts, gears, and other structural components. |