Guides / Cost
Why Your Brass Quote Expires and What To Do About It
September 21, 2026
Buyers coming to brass from plastics or steel are often caught out by the same thing: the quote has a short validity and the repeat order costs something different. Neither is a supplier being difficult.
Brass is a copper product
Free-cutting brass C360 is about 61.5 percent copper. C260 is about 70 percent. Even the zinc is a traded commodity.
Brass bar is bought by weight at a price that tracks the copper market, and that market moves on a timescale of weeks. Nothing else in a machining quote behaves like that. Machine rates are stable for a year. Tooling is stable. Labour is stable. The metal is not.
How that lands in your quote
A shop quoting your part builds the price out of metal plus conversion, where conversion is machining, finishing, inspection and packing.
The proportion between them depends entirely on the part.
A small Swiss turned hose barb. Grams of metal, a long cycle with many tools, a gauged thread. Conversion dominates. The metal is almost noise, and a copper move barely touches the price.
A heavy valve body turned from solid. Hundreds of grams of bar, much of it cut away. Metal can be more than half the price before the first tool touches it, and a ten percent copper move is a real number.
This is why two shops can give you genuinely different answers about quote validity on two different parts and both be right.
The three things that follow
Quotes expire. Thirty days is common and some shops go shorter in a moving market. A quote from three months ago is a conversation starter.
Repeat orders get re-priced. The shop is buying bar again at today’s price. This surprises buyers who expect a repeat to be automatic, and it is not a mark-up.
Bar diameter matters. A part turned from bar throws away everything outside its largest diameter. Chips have value but well below bar price, so the difference between a 30 mm bar and a 26 mm bar on a part that could use either is money you keep.
Four ways buyers take the volatility out
1. Agree a metal price basis. Split the price into conversion and metal. Conversion is fixed for the contract. Metal is recalculated against a published index at agreed intervals, monthly or quarterly.
This is standard practice in high volume brass supply and it makes both sides predictable. It also removes the argument from every repeat order, which is worth something on its own.
2. Order against a release schedule. Commit to an annual quantity, buy the bar once, and call the parts off in batches. You get one metal price for the year and the shop gets a production plan.
The trade is that you have committed. Do this where the design is stable and the volume is real.
3. Design out the waste. The cheapest metal is the metal you never buy.
Choose a bar diameter close to the part’s largest feature. Consider whether a bulky part should be hot forged to a near net shape and machined only where it matters, which changes the metal equation completely. See forging or machining a brass part.
4. Get the alloy right rather than conservative. Lead-free grades cost more per kilo than C360. That is correct and unavoidable where the standard demands it, and wasteful where it does not. Specify lead-free on the parts that need it, not across a whole product family out of caution. See leaded and lead-free brass compared.
What about the scrap
Shops keep brass swarf segregated because clean single alloy chips have real resale value. That credit is already inside the price you were quoted.
It does not change the design conclusion though. The recovery on swarf is well below bar price, so a kilo wasted is not a kilo recovered. Designing a part that starts closer to net shape beats optimising the scrap stream every time.
One practical note: mixing alloys in the swarf bin destroys that value. If you are asking a shop to run both leaded and lead-free brass, they are already managing segregation for your certificates, and the scrap stream is a second reason they take it seriously. See material certificates for brass parts.
What to tell a shop so they quote well
Three pieces of information change the number meaningfully.
The annual quantity and whether it repeats. A shop expecting the part back quarterly quotes setup differently and may propose a release schedule.
Whether the design is stable. Stability is what makes a bar purchase or a forging die sensible.
Whether you want a metal adjustment clause. Ask for it if the part is heavy. Shops that supply volume brass will have a mechanism ready.
For the full picture on where the rest of the money goes, see what drives the cost of a machined brass fitting.
Have a heavy brass part with real annual volume? Send the drawing with the yearly quantity. It changes both the quote and which shops it makes sense to send it to.
Frequently asked questions
Why does a repeat order get re-priced?
Because the shop has to buy bar again at whatever the metal costs that week. It is not a mark-up and it is not a negotiating tactic. On a heavy brass part the metal can be more than half the price before a tool has touched it, so absorbing a copper move would mean the shop working at a loss on your repeat.
How long is a brass quote usually valid?
Thirty days is the common figure, and some shops go shorter when the market is moving. A quote from three months ago is a starting point for a conversation rather than a price. If a shop offers you a long validity on a heavy part without a metal adjustment clause, check that they have understood the weight.
What is a metal price basis?
An agreement that splits the price into a metal component and a conversion component. The conversion part, machining, finishing and packing, stays fixed for the contract. The metal part is recalculated against a published index at agreed intervals. It makes both sides predictable and removes the argument from every repeat order.
Do brass chips have value?
Yes, and less than you would hope. Clean segregated brass swarf sells back at a meaningful fraction of bar price, which is why shops keep it separate. But the recovery is well below what you paid for that metal, so designing a part that wastes less bar is worth far more than the scrap credit on the waste.
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