Metal Finishing — Black Oxide, Bluing, Patina & Polish

Conversion coatings and surface work on small batches. Where plating adds a layer of a different metal, most finishing converts or colours the surface you already have — thinner, dimensionally negligible, and often the correct choice for tooling and steel parts that need to stay to size.

Black oxide coating

A conversion coating for steel. It adds essentially no thickness, which makes it the right answer for parts with tight tolerances — punches, dies, fixtures, fasteners, machine parts. The finish is a deep matte black.

Black oxide on its own offers only mild corrosion resistance. It is normally sealed with oil or wax, and we supply it oiled unless you tell us otherwise. If the part will live outdoors, plating is the better call.

Cold and hot bluing

Traditional steel finishes, most familiar from firearms and hand tools but equally at home on restoration hardware.

• Cold blue — applied at room temperature. Faster and gentler on parts with solder joints or springs, but thinner and less durable.
• Hot blue — a salt bath process producing the deep blue-black of factory firearm finishes. More durable, better colour, and the usual choice for restoration.

Both need bare, degreased steel to strike evenly. Old finish, pitting or plating must come off first, which is quotable prep.

Patina and antiquing

Chemical colouring for brass, bronze and copper. Ranges from a light warming of the surface through to deep browns and near-blacks, and it can be highlighted back on raised detail for an aged look. Common on hardware, lighting, instrument fittings and reproduction work.

Patina is a living finish. It will keep moving unless it is sealed — say if you want it lacquered and we will stop it where you like it.

Polish and prep

Available on its own or as the first stage before plating. Worth understanding: plating is a mirror, not a filler. A bright nickel finish will faithfully reproduce every scratch underneath it, so parts destined for a bright finish almost always need polishing first. If you send a part for bright plating without prep, we will quote the polishing separately rather than plate over the flaws.

What we need to quote

Photos, the base metal, and a note on the current condition — bare, painted, rusted or previously finished. Typical turnaround is five to ten business days from arrival, plus return shipping.