Carbon steel is the material you choose when strength per unit of cost is what matters. It is cheaper than stainless, stronger than aluminum, and available in grades that span from soft and formable to hard and wear-resistant. The one thing it will not do is protect itself.
Every carbon steel part we ship either gets a protective finish or goes to a customer who is applying one. Uncoated carbon steel in a damp workshop rusts, and it rusts faster than people expect.
Grades We Run
Carbon Steel Machining Capabilities
| Grades | 20# (low carbon), 45# (medium carbon), 12L14 (free-cutting) |
|---|---|
| Machining tolerance | ±0.01 mm standard |
| Surface roughness | Ra 1.6 |
| Processes | CNC turning, turn-mill compound, automatic lathe, Swiss-type, stamping |
| Typical parts | Bolts, studs, shafts, pins, bushings, nuts, sleeves, stamped plates |
| Surface finishing | Zinc plating, nickel plating, blackening, polishing |
Machining notes
Decide on the finish before you decide on the tolerance. Plating and blackening change dimensions in the same way anodizing does, and zinc plating on a thread is a classic source of a part that will not assemble. Tell us which features are functional and we will machine to a size that lands correctly after coating.
12L14 is the volume answer. Like free-cutting brass, the lead content makes it break chips cleanly and run fast — ideal for simple turned parts in quantity. For the same reason, it is usually not the right grade for a part that has to be welded, or one in skin contact.
45# will fight you if you harden it wrong. It is a hardenable grade, and hardening is a separate process from machining. If the drawing calls for a hardness, tell us at enquiry stage so the machining allowance and sequence can be planned around the heat treatment rather than after it.