C75 — high carbon unalloyed steel for flat springs, saw blades and agricultural cutting edges.
C75 per EN 10083-2 (1.0605). High carbon (0.70-0.80%) provides excellent hardness (HRC 60-63) after oil quenching. Lower alloy content than 51CrV4 means lower cost but inferior hardenability and fatigue life. Used for flat springs, band saws, agricultural blades and flexible couplings.
| Standard Body | Designation | Country / Region | Note |
|---|---|---|---|
| EN / ISO | C75 / 1.0605 | EU | |
| DIN | Ck75 / 1.0605 | Germany | |
| AISI/SAE | 1075 | USA | |
| BS | 080A72 | UK | |
| JIS | S75C | Japan | |
| GOST | 75 | Russia | |
| UNS | G10750 | USA (UNS) | |
| GB | 75 | China | |
| JUS | C.1573 | Yugoslavia | High carbon steel for springs and blades; JUS B.B1.100 |
| # | Standard Body | Designation | Country / Region | Note |
|---|---|---|---|---|
| 1 | EN / ISO | C75 / 1.0605 | EU | — |
| 2 | DIN | Ck75 / 1.0605 | Germany | — |
| 3 | AISI/SAE | 1075 | USA | — |
| 4 | BS | 080A72 | UK | — |
| 5 | JIS | S75C | Japan | — |
| 6 | GOST | 75 | Russia | — |
| 7 | UNS | G10750 | USA (UNS) | — |
| 8 | GB | 75 | China | — |
| 9 | JUS | C.1573 | Yugoslavia | High carbon steel for springs and blades; JUS B.B1.100 |
| Element | Symbol | Min % | Max % | Typical % |
|---|---|---|---|---|
| Carbon | C | 0.7000 | 0.8000 | 0.7500 |
| Silicon | Si | 0.1500 | 0.3500 | 0.2500 |
| Manganese | Mn | 0.6000 | 0.9000 | 0.7500 |
| Phosphorus | P | — | 0.0300 | — |
| Sulphur | S | — | 0.0300 | — |
| Condition | Code | Rm min MPa | Rm max MPa |
Re min MPa | Re max MPa |
A₅ min % |
Z % |
KV J |
HB min | HB max | HRC min | HRC max | E GPa |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Soft Annealed | +A | 750 | 950 | 470 | 670 | 10.0 | 30.0 | — | 220 | 270 | — | — | 210.0 |
| Q+T (spring) | +QT | 1,200 | 1,500 | 1,050 | — | 5.0 | 20.0 | — | 355 | 450 | — | — | 210.0 |
| Coolant | Soluble oil 8-12% |
| Chip Formation | Short brittle chips (hardened) |
| Tool Material | Carbide P30; TiAlN coated |
| Surface Finish | Ra 0.8-1.6 um |