Process · Grinding
Surface, cylindrical and centerless grinding for the features milling cannot reach — sub-micron tolerances, mirror finishes, and hardened parts machined to size.
Grinding removes material with an abrasive wheel rather than a cutter, so it reaches tolerances and finishes that milling and turning cannot, and it cuts hardened steel that would defeat a tool. It is the finishing process for precision features.
Capabilities at a glance
| Parameter | Range |
|---|
| Types | Surface · cylindrical (OD/ID) · centerless |
| Tolerance | ±0.002 – 0.005 mm (IT5–IT6) |
| Surface finish | Ra 0.2 – 0.4 µm |
| Flatness / parallelism | Sub-0.01 mm achievable |
| Materials | Hardened & tool steel, stainless, carbide, ceramics |
When grinding earns its place
- Tolerances tighter than IT6 or finishes below Ra 0.8 µm.
- Parts machined after hardening, to avoid heat-treat distortion.
- Sealing, sliding and bearing surfaces that must be flat and smooth.
Often a finishing step after milling or turning; see the tolerance reference for when it is required.
Frequently asked questions
When do parts need grinding instead of milling?
Grinding is used when a feature needs tighter tolerance than milling holds (IT6 or better), a very fine finish (Ra 0.2–0.4 µm), or must be machined after hardening — grinding cuts hardened steel that would defeat a milling cutter.
What tolerance and finish does grinding hold?
Routine ground tolerance is ±0.002–0.005 mm with surface finish down to Ra 0.2 µm, plus flatness and parallelism far better than as-milled surfaces.
What types of grinding do you offer?
Surface grinding for flat faces, cylindrical (OD/ID) grinding for round parts, and centerless grinding for high-volume shafts and pins.
Can you grind hardened steel?
Yes — that is grinding's main advantage. Parts are hardened first, then ground to final size and finish, which avoids the distortion of machining before heat treatment.
