Modeling Stamped Part Cost: A Working Formula
Short answer: Model stamped part cost as landed cost per good piece = (material cost ÷ material yield) + (cycle time × press hourly rate ÷ cavities ÷ yield) + secondary operations + (tooling investment ÷ lifetime volume) + scrap and freight allowances. On a typical 0.5 mm brass terminal run of 500,000 pieces, material often lands at 40–55% of unit cost, press time at 15–25%, and amortized tooling at 5–15%. Because yield, not piece price, drives the result, a 6% material utilization gain usually beats a 10% press-rate negotiation. BQUQ quotes custom stamping from one Dongguan ISO9001 factory in 12 working hours.
Why a Formula Beats a Piece Price
A quoted piece price is an output. It hides the four or five variables that actually decide whether a stamped part is cheap or expensive at your volume. When engineers model cost themselves, three things happen: they stop arguing about price and start arguing about design, they can compare a 4-cavity progressive die against a 1-cavity compound die on equal terms, and they catch the cases where a low unit price is being subsidized by an unrealistic tooling amortization.
The formula below is the one we use when reviewing a customer's RFQ internally. It is deliberately simple — arithmetic you can run in a spreadsheet — but it captures the levers that move real money: strip layout, material yield, press tonnage and speed, die maintenance, and volume.
The Core Equation
Landed cost per good piece:
C = (M ÷ Y) + (T × R ÷ (N × Y)) + S + (D ÷ V) + F
Where:
| Symbol | Meaning | Typical unit |
|---|---|---|
| M | Net material cost per part (blank area × thickness × density × price/kg) | USD/piece |
| Y | Material yield — good parts per unit of strip consumed, as a decimal | 0.70–0.90 |
| T | Press cycle time per stroke | seconds |
| R | Fully loaded press hourly rate (labor + power + overhead + depreciation) | USD/hour |
| N | Cavities (or parts per stroke in a multi-out layout) | count |
| S | Secondary operations per part (deburring, plating, tapping, reeling) | USD/piece |
| D | Total die investment, including design, build, trial and first maintenance | USD |
| V | Lifetime volume over which the die is amortized | pieces |
| F | Freight, packaging, inspection and scrap-recovery credit adjustments | USD/piece |
Note that yield Y appears twice. That is intentional. Poor strip utilization raises material cost and reduces effective press output at the same time — the double penalty is why nesting and layout decisions dominate stamping economics.
Step 1: Material Cost and Yield
Start with the blank. For a flat stamped part, net material cost per part is blank area (including carrier and web allowance) × thickness × alloy density × price per kilogram. Copper alloys run roughly 8.9 g/cm³, steel 7.85 g/cm³, aluminum 2.70 g/cm³.
Then apply yield. Yield in stamping is not "scrap rate" in the machining sense — it is the fraction of purchased strip that ends up as shipped parts. A well-nested progressive layout on a 0.5 mm brass contact might reach 78–85%. A loose layout with a wide carrier and generous edge scrap might sit at 65%.
| Layout factor | Efficient layout | Loose layout | Effect on material cost |
|---|---|---|---|
| Edge scrap allowance | 1.0–1.5 mm | 3–4 mm | +8–15% |
| Carrier width | Minimum for feed stability | Oversized | +5–12% |
| Nesting angle | Rotated to interlock | Straight rows | +6–20% |
| Strip width utilization | 80–88% | 60–70% | +15–30% |
| Scrap recovery credit | Sold back at alloy scrap price | Discarded | −5–12% net |
Two practical notes. First, scrap is not worthless — brass and copper scrap carries real recovery value, so subtract a scrap credit rather than treating offal as pure loss. Second, yield should be measured on the actual strip, not estimated from the drawing. Ask your supplier what strip width they intend to buy and how many parts fit across it.
Worked Example: 0.5 mm Brass Terminal
Assume a terminal with a blank area of 120 mm², 0.5 mm thick, brass at USD 9.50/kg, strip width 40 mm with 4 parts across, and 85% yield.
- Part volume: 120 mm² × 0.5 mm = 60 mm³ = 0.06 cm³
- Part mass: 0.06 cm³ × 8.9 g/cm³ = 0.534 g
- Gross material per part: 0.534 g × (9.50 ÷ 1000) = USD 0.00507
- With 85% yield: 0.00507 ÷ 0.85 = USD 0.00597 per part
That is the material floor. Everything else stacks on top of it.
Step 2: Press Time and Hourly Rate
Press cost per part is cycle time × hourly rate ÷ cavities ÷ yield. Cycle time comes from press speed (strokes per minute) and any indexing or reeling overhead. A 45-ton high-speed press running a progressive die might hold 300–600 strokes per minute on thin material; a 110-ton press forming 2 mm steel might run 60–120 strokes per minute.
| Press class | Typical SPM (indicative) | Loaded hourly rate (indicative) | Best fit |
|---|---|---|---|
| 25–45 ton high speed | 300–800 | USD 25–45/hr | Thin terminals, contacts, shims |
| 45–80 ton | 150–400 | USD 35–60/hr | Connector shells, clips, brackets |
| 80–160 ton | 60–200 | USD 50–85/hr | Thicker brackets, mounts, heat sink fins |
| 160–250 ton | 30–90 | USD 70–120/hr | Heavy forming, deep draws |
Using the terminal example: 400 SPM = 0.15 s per stroke, 4 cavities, 85% yield, USD 40/hr.
- Cost per stroke: 40 ÷ 3600 = USD 0.01111
- Per part: 0.01111 ÷ 4 ÷ 0.85 = USD 0.00327
Press time is cheaper than material here — a common pattern for small, high-cavity parts. It flips for large, low-cavity parts like mounting plates.
Step 3: Tooling Amortization
Die investment is a fixed cost spread over volume. The honest question is not "what does the die cost" but "over how many parts, and what happens if we don't hit that number."
| Die type | Typical investment (indicative) | Typical lead time | Amortize over |
|---|---|---|---|
| Simple blank/compound die | USD 1,500–4,000 | 2–4 weeks | 20k–100k pcs |
| Progressive die, 3–6 stations | USD 4,000–12,000 | 4–7 weeks | 100k–500k pcs |
| Progressive die, 8–15 stations | USD 12,000–35,000 | 6–10 weeks | 500k–2M pcs |
| High-speed precision progressive | USD 25,000–60,000 | 8–14 weeks | 2M+ pcs |
At USD 12,000 over 500,000 pieces, tooling adds USD 0.024 per part — four times the material cost in our terminal example. At 2 million pieces it drops to USD 0.006. This is the single most volume-sensitive term in the model, and it is why we recommend reading how short-run tooling changes the math before assuming a progressive die is always correct.
When Tooling Should Not Be Amortized
If the customer owns the die and pays for it upfront, D drops out of the unit cost entirely and the piece price becomes a pure conversion cost. That is usually the better structure for products with uncertain lifetime volume, or where the buyer wants to move the tool between suppliers. Discuss ownership, maintenance responsibility and die life expectations explicitly — see the stamping die troubleshooting guide for the failure modes that determine real die life.
Step 4: Secondary Operations, Freight and Risk
Secondary operations are frequently underestimated. Each one adds handling, a separate queue, and its own yield loss.
| Operation | Typical adder (indicative) | Notes |
|---|---|---|
| Deburring / tumbling | USD 0.001–0.005 | Volume-dependent, cheap at scale |
| Reeling / taping | USD 0.002–0.008 | Required for automated assembly |
| Selective plating | USD 0.005–0.030 | Tin, nickel, gold flash — alloy and thickness driven |
| Tapping / threading | USD 0.010–0.050 | Often better as a separate station in-die |
| 100% dimensional inspection | USD 0.003–0.015 | Only where tolerance demands it |
| Packaging and freight | 1–4% of unit cost | Air freight can exceed the part cost |
Tolerance is a cost multiplier, not a free specification. Holding ±0.02 mm on a stamped feature is routine; holding ±0.005 mm on a formed height requires tighter die work, slower speeds, more frequent maintenance, and often 100% gauging. If your drawing carries tolerances you cannot justify functionally, you are paying for them. The relationship between tolerance and cost is covered in detail in our article on high-precision stamping tolerances.
Building the Full Model: Two Scenarios
Take the same 0.5 mm brass terminal, USD 40/hr press, 4 cavities, 85% yield, USD 0.004 secondary operations, USD 0.0015 freight and packaging.
| Line item | Scenario A: 100k pcs, USD 8,000 die | Scenario B: 2M pcs, USD 8,000 die |
|---|---|---|
| Material (÷ yield) | USD 0.00597 | USD 0.00597 |
| Press time | USD 0.00327 | USD 0.00327 |
| Secondary ops | USD 0.00400 | USD 0.00400 |
| Tooling amortization | USD 0.08000 | USD 0.00400 |
| Freight & packaging | USD 0.00150 | USD 0.00150 |
| Landed cost per part | USD 0.09474 | USD 0.01874 |
Same part, same die, same factory — a 5× difference driven almost entirely by volume. This is why "what does this part cost" is an incomplete question. The complete question is "what does this part cost at this volume, with this die strategy, at this tolerance."
How to Use the Model in a Negotiation
Run the formula before you send the RFQ, then compare your numbers against the quote line by line. Three checks matter most:
1. Strip width and yield. Ask what strip width the quote assumes. If the supplier is buying 45 mm when 40 mm would work, you are paying for offal.
2. Cavity count and press class. A quote built on a 1-cavity die at 100 SPM is structurally different from one built on 4 cavities at 400 SPM. Neither is wrong; they suit different volumes.
3. Tooling ownership and amortization. Confirm whether tooling is charged once, amortized into piece price, or both. Get die ownership in writing.
For parts like custom metal stamping projects with mixed families, or stamped terminals and contacts where material grade drives most of the cost, this discipline pays back quickly. For heavier formed parts such as stamping brackets and mounts, press tonnage and cycle time move up the ranking and material yield matters less.
Design Changes That Cut Cost Fastest
- Reduce blank area by 10% — direct material saving, no tooling penalty if caught before die build.
- Improve nesting — often 5–15% material reduction with a layout change alone.
- Relax a non-functional tolerance — removes gauging and slows die wear.
- Add a cavity — halves press cost per part if press capacity allows.
- Move a secondary operation in-die — eliminates a handling step and its yield loss.
Frequently Asked Questions
Q: What percentage of stamped part cost is material?
A: On small, high-cavity parts like terminals and contacts, material typically runs 40–55% of landed unit cost at high volume. On larger, low-cavity parts such as brackets and mounting plates, material share often rises above 60% because press time per part falls relative to blank area. Measure your own ratio — it tells you instantly which lever to pull.
Q: How do I decide between a compound die and a progressive die?
A: Compound dies are cheaper to build and faster to lead, suiting volumes under roughly 100,000 pieces or simple flat geometries. Progressive dies cost more upfront but deliver lower cycle time and fewer handling steps, so they win above a few hundred thousand pieces. Model both with the formula and compare total landed cost at your realistic lifetime volume, not at peak forecast.
Q: Does higher tolerance always mean higher cost?
A: Not automatically, but usually. Tolerances tighter than the process naturally holds force slower press speeds, more frequent die maintenance, additional gauging, and sometimes a second operation. The cost step is not linear — it jumps when you cross from "capable by default" to "requires control." Specify only what the assembly function requires and document why.
Q: How should tooling cost be handled for a product with uncertain volume?
A: Pay for the die separately and own it. This removes amortization from the piece price, keeps unit cost stable if volume drops, and lets you move the tool to another supplier if needed. Confirm die ownership, maintenance responsibility, expected stroke life and storage terms in the purchase agreement before the build starts.
Q: What lead time should I plan for on a new stamped part?
A: For a simple die, plan 2–4 weeks for tooling plus 1–2 weeks for sampling and approval. Progressive dies typically need 4–10 weeks depending on station count. Add time for material procurement if you specify a non-stock alloy. BQUQ returns quotations in 12 working hours and supports flexible MOQ for first builds.
Related Resources
- About BQUQ and our four Dongguan production lines: /about/
- Custom metal stamping capabilities and tolerances: /custom-metal-stamping/
- Stamped terminals, contacts and precision electrical parts: /stamping-terminals-contacts/
- Stamped brackets, mounts and structural parts: /stamping-brackets-mounts/
- Industry trends in metal forming and sourcing: /industry-dynamics/
- Full technical article archive: /bquq-blog/
- Frequently asked questions and quoting process: /faq/
- Case studies from production: /case/
- Contact our engineering team: /contact/
Authored by the BQUQ Engineering Team. BQUQ (Dongguan) runs CNC machining (±0.005 mm), metal stamping, custom springs, and heat sink production in one ISO9001 factory. Source-direct from Dongguan, China — quote in 12 hours: sc@bquq.com | WhatsApp +86 13713157787 | www.bquq.com
