Plating shops often teach a metal-mass estimate: plated area times thickness times the density of the metal. That line is real. It is not the full quote, and it is not a factory price list.
Use this checklist for OEM stamped and fabricated parts that need zinc, nickel, tin or another finish named on the drawing. It is for writing a comparable RFQ, not for choosing a bath, an additive brand or a gold-utilization slogan. You do not need every line filled in before you send a drawing; if a point is still open, say so and ask.
Short answer: what the RFQ must include
Send the part drawing, base metal, the plating metal, a thickness note, and which faces are plated versus masked. If quotes should include cleaning, thickness reports or salt spray, say so on the same package.
The finisher should not have to guess whether the job is a flash for appearance, a solderable tin, a nickel barrier, or a precious-metal thickness that moves with the metal market.
- Base metal, temper and any finish-sensitive fits.
- Plating metal and underplate, with a named spec if you have one.
- Min thickness, and the faces that will be measured.
- Rack, barrel, or let engineering propose from geometry and volume.
- Masking map, and whether cleaning, reports or tests are in the price.
Metal mass is one line, not the quote
Deposited metal can be estimated from plated area, thickness and the published density of that metal. Multiply by a metal price and you have a metal line. Pretreatment, racking or barrel loading, masking, bath chemistry, utilities, wastewater and yield are separate.
Two quotes that only say nickel plate or gold plate are not comparable. One may assume a flash and barrel; the other may assume a min thickness, rack, underplate and a thickness report.
- Area: which faces, holes and edges are actually plated.
- Thickness: min, average or flash. Write the rule.
- Density and metal price belong to the named metal, not to a slogan.
Name the metal, thickness and underplate
Zinc, nickel and tin are common on stamped steel, copper and electronic parts. If the drawing names gold or silver, the metal line follows thickness and plated area more than the additive brand. Do not copy a chemical-supplier coupon as the production thickness.
An underplate such as nickel under tin or gold changes both function and cost. Write it. Buildup changes hole fit. State whether dimensions apply before or after plating.
Rack, barrel, masking and contact faces
Barrel plating is often cheaper per piece on small hardware and has more thickness scatter. Rack plating costs more in labor and can hold thickness on named faces. Geometry, volume and the thickness note decide the route, not a default shop habit.
Mark pads that must stay solderable, conductive or unplated. Selective plating and masking are extra operations. A part can meet a metal-mass estimate and still fail the joint if the contact face is wrong.
Write what the quoted price includes
Ask whether the number includes pretreatment, stripping of bad lots, thickness measurement, salt-spray or adhesion checks, and any precious-metal surcharge. If those sit outside the piece price, two low quotes are not the same job.
- Cleaning and de-oiling after stamping.
- Thickness method, measured faces and sample quantity.
- Whether salt spray or adhesion is inside the quote.
- How precious-metal market moves are billed, if that metal is specified.
| Buyer requirement | Why it matters | What to write |
|---|---|---|
| Thickness | Min versus flash changes metal mass and function | Spec, min thickness, measured faces |
| Plated area | Hidden faces and holes still consume metal | Which faces, holes and edges are plated |
| Rack or barrel | Labor and thickness scatter differ | Method, or ask engineering to propose |
| Masking or selective | Extra labor; pads and fits change | Map on the drawing |
| Precious metal | Price follows metal and thickness | Metal, underplate, thickness, surcharge rule |