Three facts that decide this page
- Brass is pressed, not just cut: small electrical and hardware parts are the classic brass stamping because the material coins and forms cleanly at high speed.
- Ganesh runs mechanical presses from 20 T to 300 T, a 250 T punching press and an in-house tool room at Mumbai (Vasai), so tool design, build and maintenance stay under one supplier.
- CuZn37 forms well and is the general-purpose grade; CuZn39Pb2 is freer-cutting and easier to shear but carries lead, which is restricted for some electrical and consumer applications. Brass work-hardens, so multi-stage drawing needs inter-stage annealing. Scrap is valuable, which changes the economics of nesting and strip layout.
What changes when you stamp brass
CuZn37 forms well and is the general-purpose grade; CuZn39Pb2 is freer-cutting and easier to shear but carries lead, which is restricted for some electrical and consumer applications. Brass work-hardens, so multi-stage drawing needs inter-stage annealing. Scrap is valuable, which changes the economics of nesting and strip layout.
The commercial consequence is that brass is priced on its own material line, not blended into a steel rate. Material grade, thickness, tolerance and finish are quoted separately from conversion, so a change of specification is visible in the price.
Tolerance, edge and finish
Ganesh quotes to the drawing first and to ISO 2768 general tolerances where the drawing is silent. For brass stamping, the practical starting points are in the table below. They are starting points, not a guarantee: the part geometry, thickness and fixturing decide what can actually be held, and the quotation states the tolerance offered.
How Ganesh runs this route
Blanking, piercing, forming and drawing are quoted as one press route; the number of stations, not the tonnage alone, usually decides whether a part is worth tooling. Lead-bearing CuZn39Pb2 machines and shears more freely but is restricted in some markets under RoHS and REACH, so the grade has to be chosen against the destination market, not only the drawing. The route is quoted as one sequence so the customer does not have to coordinate a cutter, a former, a welder and a coater.
When stamping is the wrong route for brass
Stamping brass is the wrong route where the part is a simple flat contact or washer in low volume; laser cutting or waterjet avoids a tool. It is also wrong when the alloy cannot meet the market's substance restrictions.
A manufacturability review before quotation is the cheapest place to find this out. Send the drawing, material, finish and annual quantity and the review comes back in writing.
Typical parts
- Electrical contacts and terminals
- Hardware and fittings
- Decorative plates
- Small drawn cups
Decision rule: when to choose stamping
Use stamping when the geometry is frozen and the annual quantity repays the tool. As a working rule, a simple bracket in a single-stage tool becomes cheaper than laser-cut-and-formed at roughly 3,000–8,000 parts a year; a progressive tool needs more volume because the tool itself costs more. Below that range, laser and bend keeps the cash free and the revision cheap. Between the two, quote both and compare total cost over the programme life, not the first order. For brass the practical constraint is alloy restriction and tarnish: the grade has to satisfy the destination market's substance rules, and the surface needs protection if it must stay bright. Brass is usually a volume material by nature, so the process decision is often already made by the part family; the real choice is the alloy and the temper, and whether the destination market permits the lead content.
What to put on the drawing
State the material grade and blank thickness, the tolerance on every functional feature, the burr direction and height where it matters, the grain direction if the part is drawn, and whether the tool is customer-owned or supplier-built. Name the inspection level. If the part will be welded, say so, because the burr and the flatness that a welding fixture needs are not the same as for a plain bracket.
Quality evidence and inspection
Inspection covers dimensional features, burr height, material thickness and hardness at sample frequency, plus a first article report before production. Ganesh holds tools in the in-house tool room, so die maintenance records and tool history are available with the part. PPAP documentation is available where the programme requires it.
What drives the cost
Cost splits into material, tooling, press time, secondary operations and inspection. Tooling is a one-off and is quoted separately, so the piece price only makes sense against an annual quantity. Press time is driven by stroke rate and the number of stations, not by part weight. Secondary operations such as deburring, tapping, welding and coating often exceed the press cost on a small part. On brass, material is quoted as its own line at the prevailing rate for the grade and thickness, so a change of specification is visible rather than hidden in a blended rate.
| Specification | brass stamping | Ganesh limit or note |
|---|---|---|
| Grades | CuZn37 and CuZn39Pb2 strip to ASTM B36 / EN 1652 | Grade per drawing |
| Thickness | 0.3–3 mm strip and sheet | 20–300 T mechanical, 250 T punching |
| Tensile / property | 300–450 MPa depending on temper | 8.4–8.5 g/cm³ density |
| Alloy | CuZn37, CuZn39Pb2 | Lead-free grades where RoHS/REACH applies |
| Thickness | 0.3–3 mm | Below 0.3 mm handling, not the press, becomes the limit |
| Formability | Excellent for coining and drawing | Annealing between draws where depth needs it |
| Stamping | 20–300 T mechanical, 250 T punching | Tonnage sized from perimeter, thickness and shear strength |
| Tolerance basis | ISO 2768-m unless drawing states otherwise | Critical features inspected |
| Finish | Degrease and passivate, or coat where tarnish matters | Specified per part |
Sources and review
- ASTM B36/B36M — Brass plate, sheet, strip and rolled bar · reviewed 2026-11-03
- EN 1652 — Copper and copper alloys, plate, sheet, strip · reviewed 2026-11-03
- EU RoHS Directive 2011/65/EU · reviewed 2026-11-03
- ASTM B36 brass strip and EU RoHS restrictions · reviewed 2026-11-03
Combines Ganesh machine limits (20–300 T mechanical, 250 T punching) with brass grade and property data. The "what changes" section is written for this material–process pair and is not reused on another page.
Send the drawing and we will check the route
Material, thickness, tolerance, finish and annual quantity are enough for a manufacturability review. Tooling is quoted separately from the piece price.
Request a quote