Production Machining

Setup divides

Programming, first-off checks and fixture set-up are paid once per batch, not once per piece. Ten pieces carry a tenth of it each; five hundred carry almost none.

Cycle time falls

Dedicated workholding, a proven program and optimised toolpaths take seconds out of every part. This is a separate saving from the setup one, and it is the reason a volume price is not just the prototype price divided.

Material position changes

Stock bought for a scheduled annual quantity is not priced like a single bar cut for one part.

What does not change

Tolerance, finish and inspection scope. If those move, the volume price moves with them — which is why they are agreed before the quote, not after.

Ask for the volume price at the volume you actually run. A quote taken at 25 pieces and multiplied out is the single most common reason a production programme looks more expensive than it is.

Annual programmes are priced by engineering review against your release schedule, material position and tooling plan. That is the number that goes on the blanket order — the instant estimate is indicative and is not binding until an engineer has reviewed the part.

Critical-to-quality characteristics

You identify the features that fail the part in service. Those carry SPC with Cpk ≥ 1.33 and are monitored across the run, not just at the start.

Everything else

Sampled against an inspection plan agreed in the RFQ: which characteristics, at what frequency, and what happens to a batch that falls outside. In-process CMM sampling runs against the same plan.

First article

FAI in AS9102 format for a new part number and again on a revision change. Who signs it off, and whether volume may start before that signature, is stated in the order.

Records

Mill certificates are retained seven years and tied to heat or lot number, so a question raised two years into a programme can still be answered.