Carbon & Engineering Steel Machining
Drive shafts, gears, load-bearing fixtures, and parts requiring heat treatment to high hardness.
Grades we run
| Grade | When we use it |
|---|---|
| S45C / C45 | Medium-carbon structural steel — the everyday choice for shafts, pins and plates |
| SCM440 / 42CrMo4 | Through-hardening alloy steel for shafts and highly stressed parts |
| SKD11 / SKD61 | Tool steels for wear-resistant fixture details and tooling components |
Machinability
S45C machines readily in its as-supplied condition. Alloy and tool steels are tougher on tools, and once hardened they are slower again.
The usual route for a hardened part is to rough-machine, heat treat, then finish the features that need accuracy — because heat treatment can move a part. Heat treatment and nitriding are coordinated through our partners; machining after heat treatment is done in-house.
For profiles, slots and sharp internal features in hardened tool steel, where cutting force would be a problem, we use our in-house wire EDM.
Tolerance & finish
±0.01 mm as standard, ±0.005 mm on request where the feature allows. Ra 1.6 as-machined, Ra 0.8 by fine turning or milling, to Ra 0.4 on flat faces and straight round parts up to Ø40 mm by in-house precision grinding — often the finishing step after hardening.
Surface treatments
Coordinated, inspected on return
Heat treatment and nitriding, plating (including hard chrome), and powder coating. Carbon steel rusts, so tell us how the part should be protected for shipping and service. Laser marking in-house.
Design tips
- State the required hardness (e.g. HRC range) and which features must be finished after hardening.
- Allow grinding stock on features that will be ground after heat treatment.
- Avoid sharp internal corners on parts that will be hardened — they concentrate stress and can crack.