Tool Steel vs Spring Steel
Tool steels are designed for cutting, forming, and shaping other materials — they prioritise hardness and wear resistance. Spring steels are designed to repeatedly flex without permanent deformation — they prioritise high yield strength and fatigue life.
Side-by-side comparison
| Attribute | Tool Steel | Spring Steel |
|---|---|---|
| Carbon content | 0.7–1.5% | 0.5–1.0% |
| Key alloying elements | Cr, W, Mo, V | Si, Mn, Cr |
| Hardness (after HT) | 58–65 HRC | 45–55 HRC |
| Yield strength | Very high | Very high (must spring back) |
| Toughness | Moderate | High |
| Fatigue resistance | Moderate | Excellent |
| Common grades | D2, H13, M2, A2, O1 | EN42J, EN45, EN47, SUP9, 9260 |
| Common uses | Punches, dies, blades, moulds | Leaf springs, coil springs, clutch plates |
When to choose Tool Steel
Use tool steel when the part must cut, shear, punch, or form other materials — cold-work dies, blanking punches, knives, moulds.
Buy Tool Steel on MetaleMartWhen to choose Spring Steel
Use spring steel for parts that must flex repeatedly under load without taking a permanent set — leaf springs, coil springs, clips, agricultural blades.
Buy Spring Steel on MetaleMartFrequently asked questions
Can tool steel be used as a spring?
Generally no — tool steels are too brittle. They will crack rather than flex back.
Can spring steel be used as a knife?
Yes — many machetes and large knives are made from spring steel because of its toughness, though edge retention is inferior to true tool steel.
Which is harder to machine?
Tool steel in its annealed state machines reasonably well. Spring steel in the hardened state is very difficult to machine — work it before hardening.