Black Oxide Treatment is specified for a reason: corrosion resistance, wear, appearance, cleanliness or electrical behaviour, and the wrong choice costs more than leaving the part as machined. Designed for medical device components, this Black Oxide Treatment is produced in aluminium with a clear or coloured anodised layer with surface treatment applied after final machining with documented thickness control. The figures below are the ones recorded at tryout rather than theoretical values.
Tolerance is applied where it does work rather than across the whole drawing. Critical features are held to coating thickness ±5 µm, non-critical dimensions follow the general machining tolerance, and the difference is stated in the quotation rather than discovered later.
Specification
| Process | Surface treatment applied after final machining with documented thickness control |
|---|---|
| Material / configuration | aluminium with a clear or coloured anodised layer |
| Size / capacity | hard anodising to 50 µm |
| Tolerance | coating thickness ±5 µm |
| Surface finish | anodised, plated, passivated or coated |
| Application | black oxide treatment for medical device components |
| 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 surface treatment applied after final machining with documented thickness control. 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.
- Wear surfaces on moving parts.
- Corrosion protection for outdoor use.
- Hygienic finishes for food contact.
- Colour coding of assemblies.
- Electrical insulation of housings.
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
Does finishing change part dimensions?
Yes, and the direction depends on the process. Anodising and plating add material, so threads and bores are masked or machined undersize, while electropolishing removes a small amount.
When is passivation enough instead of plating?
For stainless steel in most environments, passivation is sufficient and cheaper. Plating is needed when wear resistance or electrical properties are the actual requirement.
What file formats do you need for a quotation?
STEP or IGES for the 3D model and a PDF drawing with tolerances, material and surface finish called out. Native files from SolidWorks, Creo or Inventor are also accepted.
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.
