Cost Estimating

Cost Estimating for Precision Springs and Stampings: Building a Defensible Quote

Break unit cost into material, machine time, tooling wear, secondaries, and scrap, then assemble a line item quote that survives purchasing pressure and the first production lot.

A defensible quote for precision springs or stampings breaks into five buckets: material at 30 to 50 percent of unit cost, press or coiler time at 20 to 30 percent, tooling amortization and maintenance at 10 to 20 percent, scrap and secondary operations at 5 to 15 percent, and overhead plus margin on top. Estimators who quote from a single blended shop rate lose money on short runs and lose orders on long ones. Build each bucket separately from its own data, then stress test the total at plus and minus 25 percent volume before the quote leaves the building.

Quote material at consumed weight, not part weight. A stamped part at 45 percent strip utilization consumes 2.2 times its own weight in coil. Current ballpark pricing: music wire around $2.20 per lb, 302 stainless wire $4.50 to $6.00, phosphor bronze strip $7 to $9, beryllium copper $16 to $20. Take a scrap reclaim credit on the skeleton, usually 15 to 25 percent of purchase price for steel and 40 to 60 percent for copper alloys. The Coil Feed Yield calculator gives buy weight per thousand parts; multiply by mill price plus 3 to 8 percent for slitting, certification, and freight.

Machine cost is hour rate divided by net good parts per hour. A 60 ton progressive press carries a fully burdened rate of $85 to $140 per hour once you load depreciation, floor space, power, and an operator shared across 4 to 6 presses. At 5,674 net parts per hour and $110 per hour, press cost is $19.40 per thousand. CNC coilers run $60 to $95 per hour at 60 to 180 parts per minute depending on wire size. Use the Stamping Press Throughput calculator to get net rate from realistic uptime; quoting nameplate speed is the most common way to underquote by 20 percent.

Tooling shows up twice: the die build and the die wear. A progressive die runs $40,000 to $250,000 depending on stations and tolerance class; decide up front whether the customer buys it or you amortize it, because amortizing $120,000 over 2 million pieces adds $60 per thousand. Wear is separate and permanent: sharpening every 300,000 to 1,000,000 hits at $500 to $1,200 per event, plus punch and section replacements. The Tooling Wear Cost calculator converts a maintenance log into dollars per thousand hits, commonly $1.50 to $6.00. Quotes that omit wear cost look profitable for a year, then bleed.

Secondary operations carry lot minimums that wreck small order economics. Stress relieving is cheap per piece in a full furnace, $0.002 to $0.010, but a heat treater's $175 minimum lot charge makes 2,000 pieces cost $0.088 each; the Heat Treat Load calculator shows when batching orders restores the economics. Plating behaves the same way: barrel zinc runs $0.01 to $0.04 per piece at volume, while selective gold on connector contacts is priced by plated area and gold spot, easily $0.05 to $0.30 per piece. The Plating Cost calculator prices per piece from area, thickness, and metal price instead of guessing from the last invoice.

Setup and scrap are volume dependent, so quote them per lot, not per piece. A 4 hour die change at $95 per hour is $380: that is $0.038 per piece on a 10,000 piece release and $0.0008 on a 500,000 piece blanket. The Setup Changeover Time calculator lets you quote each release quantity honestly. Price scrap at your demonstrated fallout, not your goal; if the last three runs averaged 1.4 percent, quoting 0.5 percent donates the difference to the customer. The Progressive Die Scrap calculator turns run history into a scrap dollar line you can defend at contract review.

Five failure modes account for most bad quotes. Quoting nameplate SPM instead of demonstrated rate, worth 15 to 25 percent of machine cost. Ignoring coil end and threading losses, 1 to 2 percent of material. Missing inspection labor on tight tolerance work; a job needing 100 percent optical sort can add $2 to $8 per thousand, and the Inspection Bottleneck calculator flags when sorting, not stamping, paces the job. Skipping material surcharges on nickel alloys, which have moved 30 percent in a single year. And assuming the quoted scrap rate applies from stroke one, when the first lot typically runs double.

Assemble the quote as visible line items: material with reclaim credit, press time at net rate, tooling amortization or a separate tooling PO, wear cost, secondaries, setup per release, and scrap at demonstrated rate, then overhead at 15 to 25 percent and margin at 10 to 20 percent depending on volume and competition. A line item quote survives purchasing pressure because you can trade specific terms, larger releases against setup cost or customer owned tooling against amortization, instead of discounting blindly. Rerun the numbers after the first production lot; if actual cost lands more than 5 percent off the quote, fix the estimate model, not just the price.

Published 2026-07-02.