A Centreless Grinding Machine is the finishing operation used when tolerances or surface finish are beyond what cutting tools achieve reliably, particularly on hardened steel. Supplied to aerospace suppliers, this Centreless Grinding Machine is configured with an angular head for shoulder grinding. precision grinding with controlled wheel dressing and coolant filtration is carried out on equipment that holds ±0.002 mm across a full shift, not only on a first piece.
Tolerance is applied where it does work rather than across the whole drawing. Critical features are held to ±0.002 mm, non-critical dimensions follow the general machining tolerance, and the difference is stated in the quotation rather than discovered later.
Specification
| Process | Precision grinding with controlled wheel dressing and coolant filtration |
|---|---|
| Material / configuration | an angular head for shoulder grinding |
| Size / capacity | roundness within 0.002 mm |
| Tolerance | ±0.002 mm |
| Surface finish | ground finish, Ra 0.05–0.4 µm |
| Application | centreless grinding machine for aerospace suppliers |
| Inspection | Dimensional report, material certificate, first article report on request |
| Lead time | 7–15 working days for samples, 3–4 weeks for production |
| Minimum order | 1 piece for prototypes, from 50 pieces for production pricing |
Manufacturing process
Work is carried out with precision grinding with controlled wheel dressing and coolant filtration. Tooling, speeds and fixturing are recorded with the part number, so a repeat order starts from a proven process instead of a fresh setup.
Material is purchased against a certificate and checked on receipt, so the composition is known before any cutting starts. Work in progress is identified by part number and operation, and the finished parts are deburred, cleaned and protected before they leave the machine area.
Typical applications
Most of the work supplied in this category falls into the following examples.
- Hardened gauge blocks.
- Bearing journals and shafts.
- Die and punch details.
- Precision spacer rings.
- Hydraulic spool valves.
Quality control and documentation
Critical features are measured on calibrated equipment in a controlled room, and the results are filed with the job so that a repeat order can be compared with the first.
Material certificates to EN 10204 3.1, dimensional reports and first article inspection reports are issued with the shipment where the application requires them. Calibration dates and measurement uncertainty are recorded alongside every result.
Ordering, lead time and packaging
Packaging is specified by the part: individual protection for finished surfaces, separation for assemblies, and export crating with a packing list for shipment.
Frequently asked questions
When is grinding necessary instead of hard turning?
Below about IT5, or when the material is above 55 HRC. Grinding gives consistent size over long runs and produces finishes down to Ra 0.05 µm that cutting cannot reach reliably.
Does grinding burn hardened steel?
It can, which is why wheel grade, dressing and coolant delivery are controlled together. Parts are inspected for temper burn when the application is safety critical.
Do you keep tooling and programmes for repeat orders?
Fixtures, tool lists and verified CAM programmes are retained for the life of the part number, so a repeat release runs on the same setup as the first batch without a new proving run.
Drawings are reviewed for manufacturability before quotation, and any feature that adds cost without adding function is pointed out at that stage rather than after the parts are made.
