Mirror Polished Gold PVD Stainless Steel Castings: Buyer FAQ

Yes, as long as every visible surface can be reached by polishing tools. PVD is a very thin film (well under 1 µm) that copies the surface underneath — it does not fill or hide anything.

So a mirror gold result needs a true mirror polish first. Any pore, pit, weld line, parting line or polishing mark that is left on the steel will still be visible after coating, and gold often makes it more noticeable than bare steel. Before quoting, we check the 3D model for areas a polishing wheel cannot reach, such as tight inner curls and deep undercuts.

Mostly so every visible surface can be polished, and so each casting fills cleanly. A sculptural shape cast in one piece usually has areas that no polishing tool can reach.

Splitting the design into a few castings lets each piece be polished all the way round before assembly. Smaller, more uniform castings also have fewer thick-to-thin transitions, where shrinkage and porosity tend to form. The trade-off is more joints and one tool per casting, so we suggest split lines at natural features (a stem meeting a branch, a tray meeting its arm) where a joint looks intentional.

Threaded (screwed) joints are usually easier and cheaper when the part must stay mirror bright. With welding, every seam must be blended and re-polished to a mirror before coating, which is slow in tight corners.

A hidden threaded joint uses a stud on one part and a tapped boss on the other, with the joint line placed at a natural feature. It avoids weld heat tint and post-weld polishing, and it lets the product ship flat-packed. Welding still makes sense on open, easy-to-reach joints, or where the structure needs one rigid piece. Many designs end up using both.

Gold-colour PVD nitride coatings on 304 or 316 stainless steel are widely used on cutlery and tableware, but food-contact compliance has to be shown for your finished part. Ask for migration testing to the rules of your market on coated samples, for example US FDA requirements or EU Regulation 1935/2004 / LFGB.

We recommend agreeing on the test standard at quotation stage, so samples are made and tested the same way as the mass-production parts.

Good PVD is hard and well bonded, but strongly alkaline commercial detergents and high wash temperatures can dull or discolour it over many cycles. Wear usually starts at edges and at any polishing defects under the coating.

If dishwasher use is a requirement, put it in the specification: agree on a cycle test on coated samples before mass production, avoid clear lacquer or anti-fingerprint top coats unless they are tested too, and give the end user simple care instructions.

304 (cast grade CF8) is usually enough for indoor food service; choose 316 or 316L (CF8M / CF3M) for salt, chlorides or coastal use. 316 contains molybdenum, which gives better resistance to pitting from salt, chlorinated cleaners and acidic foods.

Both grades cast well with the silica sol process and both mirror polish well. 316 costs a little more per kilogram, so the choice usually depends on where and how the product will be used and cleaned.

The main cost drivers are casting weight, the number of separate castings (each needs its own tool), polishing hours, and how many parts fit on each PVD batch. Assembly and protective packaging add to that.

Ways to bring the cost down without changing the look on display:

• Merge or simplify small castings to reduce tooling.
• Use a brushed or bead-blasted finish on faces nobody sees, such as the underside of a base.
• Design out deep inner curls that need hand polishing.
• Use threaded assembly instead of welding plus re-polishing.
• Make simple straight parts from stainless tube or plate and cast only the sculptural parts.

We send these options with the quote so you can compare finish against price.

For the casting stage, our standard times are 5–7 business days for tooling, 7–10 business days for samples after drawing approval, and 3–5 weeks for production. Mirror polishing, PVD coating, assembly and any food-contact or dishwasher testing add time on top.

We confirm a full timeline (drawing approval → tooling → samples → coating → testing → mass production → shipping) with each quote, based on the number of parts and the finish.

Send a 3D file (STEP preferred) and a rendering or photo of the finished look, plus quantity, material and finish. For gold finishes, describe the shade (bright yellow gold, rose gold, champagne) or send a colour sample, because PVD shades vary.

Also tell us about food contact, dishwasher or outdoor use, any load or stability requirement (for example, tall stands that must not tip over), and how each piece should be packed. With this we can review the design for casting and polishing within 24 business hours.