Black Oxide Finishing
Black Oxide Finishing
Black oxide for functional metal parts.
Specify a dark finish for steel components without treating appearance as a corrosion guarantee. Send the alloy, drawing and service environment so the blackening route and protective after-treatment can be reviewed together.
Confidential files. Optional NDA available.
Machined steel fittings, tooling components and assemblies where dark appearance and fit preservation matter.
Outdoor exposure, frequent washdown or a specified corrosion test needs a separately agreed protection system. A black surface alone is insufficient.
What this process does
Black oxide is a surface conversion treatment for compatible ferrous alloys. The selected chemistry and protective oil, wax or sealer affect the finished result; cold blackening and hot or mid-temperature oxide processes should not be treated as interchangeable.
Choose the route from your requirements.
Use these points to prepare an enquiry. The selected process, material compatibility and acceptance criteria should be confirmed for your drawing.
On smaller screens, scroll the table horizontally.
| Your requirement | What to specify | What to review |
|---|---|---|
| Carbon and alloy steel | Identify grade, hardness and prior treatment. | Select a compatible blackening and cleaning route. |
| Stainless steel | Identify the exact grade. | Stainless requires suitable chemistry; do not substitute a carbon-steel route. |
| Appearance and protection | Supply a sample, blackness requirement and allowable oil residue. | Approve appearance separately from corrosion acceptance. |
| Precision interfaces | Mark bearing seats, threads and mating diameters. | Review preparation and final fit; do not assume zero dimensional effect. |
Still comparing routes? Explore the surface finish guide or send your drawing for review.
Protect the features that make the part work.
Mark the surfaces that carry function, fit and appearance. A clear drawing helps separate essential requirements from unnecessary processing.
Sealer compatibility
Oil residue may conflict with adhesive bonding, painting, cleanliness or handling requirements. State the next operation before selecting the after-treatment.
Mixed assemblies
Identify dissimilar inserts, welds and retained components. A process suitable for the main body may not suit every exposed material.
Repeat appearance
Surface condition influences the result. Identify cosmetic faces and agree a reference sample for repeat orders.
Agree the evidence before production.
Inspection should answer the requirements on your order. Define the method and acceptance criteria when a characteristic is important to the application.
- Approved blackening route and after-treatment recorded
- Visual comparison on identified cosmetic faces
- Critical dimensions checked after finishing
- Corrosion test method, duration and acceptance agreed only if required
Testing and documentation are confirmed in the quotation. A finish name or reference image does not establish certification, performance or compliance.
From drawing to an agreed finish.
Send the part context
Share the drawing, material, quantity and operating environment. Identify cosmetic and functional surfaces.
Review the process
Resolve preparation, access, masking and the sequence with machining or other finishing operations.
Confirm acceptance
Agree samples, measurements and documentation. Record the approved drawing revision and open requirements.
Release the order
Confirm the quoted route, schedule and packing requirements before work starts.
Is black oxide rust-proof?
No. Protection depends on substrate, preparation, sealer and exposure. Specify the environment and any required test; do not use colour as evidence of corrosion performance.
What should I send for a quotation?
Send the drawing revision, material grade, quantity and steel grade and heat-treated condition, indoor, outdoor, fluid or handling exposure. Mark the required surfaces and any acceptance tests. Include your target date and shipping destination.
Can I send parts that are already manufactured?
State that the parts are customer-supplied and include their current condition, existing coatings and dimensions. Acceptance, incoming inspection and the finishing route need confirmation before shipment.
Can you provide a specific inspection report?
List the required characteristics, test methods, sample quantity and report format with the enquiry. The quotation should confirm the agreed inspection scope; additional tests are not implied by the service name.
What affects price and lead time?
Part size, quantity, incoming condition, preparation, masking, finish requirements and inspection scope all affect the route. Share the complete specification so cost and schedule can be confirmed for the order.
Ready to finish your parts?
Send your drawing, material and quantity for a finishing quote.
Confidential files. Optional NDA.
Compare related services.
Technical background: these sources explain process principles. Supplier examples do not establish ProleanTech equipment, certification or project capability.