Short answer: मेटल स्टॅम्पिंग coil yield is the percentage of purchased strip that becomes usable parts after blanking, carrier, pitch, edge trim, setup scrap, and rejected pieces are removed. A quote should state the assumed material grade, coil width, strip layout, pitch, expected scrap rate, and whether scrap value is credited back to the buyer.
Material is often the largest variable in a stamped part quote. Two suppliers can quote the same drawing with different unit prices because they assume different strip widths, nesting direction, carrier size, scrap credit, or setup loss. A buyer does not need to design the strip layout, but the RFQ should give enough detail for the पुरवठादार to explain the material yield assumption.
Use this page with the quote तुलना मार्गदर्शक, cost reduction DFM guide, प्रोग्रेसिव्ह डाय stamping cost guide, and strip layout carrier design guide.
What belongs in a coil yield calculation?
| Factor | Why it changes yield | RFQ note |
|---|---|---|
| Coil width | Too much side margin wastes strip; too little margin can cause feed instability. | Ask whether the quote assumes standard coil width or slit-to-width material. |
| Pitch | Pitch controls how much material advances for each part or part set. | Review pitch when part length, feed direction, or nested orientation changes. |
| Carrier and pilots | Progressive dies need carrier material, pilot holes, and scrap strength. | Do not compare yield without knowing whether the part stays on carrier. |
| Blank nesting | Rotating or alternating parts can reduce waste, but may affect grain direction. | State whether grain direction, bend direction, or cosmetic direction is fixed. |
| Setup and restart scrap | Short runs lose more material to setup, first-piece checks, and coil changes. | Ask whether setup scrap is included in piece price or charged separately. |
Simple yield formula for buyers
A practical buyer-side estimate is:
Usable part weight divided by purchased material weight equals material yield.
For a more useful RFQ discussion, separate the loss into blanking scrap, carrier scrap, side trim, setup scrap, and quality loss. A part with 65 percent theoretical yield may still quote well if the material is low cost and the die runs fast. A part with 85 percent theoretical yield can still be expensive if it needs slow feeding, frequent setup, or secondary sorting.
Scrap rate is not only a material issue
Scrap rate also reflects process stability. Burr growth, misfeeds, sensor trips, weak carrier strips, cracked bends, plating rejects, and mixed revisions can all create nonconforming parts. When the quote includes a scrap allowance, ask what type of scrap it covers. Material skeleton scrap is normal. Process scrap after first article approval should be monitored and reduced.
For quality-related scrap, connect the quote with the defects troubleshooting guide, SPC and process capability guide, and control plan checklist.
When a lower yield can still be the better quote
A पुरवठादार may choose a wider carrier, larger bridge, or less aggressive nesting to protect feed reliability. That can increase material scrap but reduce downtime, broken punches, misfeeds, and customer escapes. For high-volume terminals, clips, and thin strip parts, feed stability may matter more than squeezing the last percent of theoretical material use.
Good quote comparison looks at total cost: material, tool cost, run speed, maintenance, inspection, finish, packaging, and rejection risk. If the buyer only pushes for the highest material yield, the पुरवठादार may remove carrier support that the die needs to run consistently.
Questions to ask before approving a quote
- What material grade, thickness, temper, and coil width are assumed?
- Is the strip slit to width or purchased in a standard width?
- What is the estimated material utilization or scrap percentage?
- Does the quote credit scrap value, keep scrap with the पुरवठादार, or ignore scrap credit?
- How much setup scrap is assumed for each run or coil change?
- Does the part require fixed grain direction, burr direction, or cosmetic orientation?
- Can small drawing changes improve nesting without affecting function?
Coil yield RFQ checklist
Send the 2D drawing, 3D model if available, material grade, thickness, finish, annual volume, order release quantity, critical bend direction, burr direction, cosmetic side, and any existing strip layout or sample photos. If you are comparing suppliers, include the quoted coil width, scrap assumption, and whether scrap credit is included.
For a cost review, send the drawing and current quote assumptions through the contact page. If the part is already in production and scrap is high, use the RFQ form to include photos of strip scrap, rejected parts, and the current process issue.
FAQ: coil yield and stamping scrap rate
What is a good coil yield for स्टॅम्प केलेले भाग?
There is no single good yield. It depends on part shape, carrier needs, material cost, grain direction, strip width, and production volume.
Should buyers ask for the strip layout?
For high-volume parts, yes. A strip layout helps explain material use, feed direction, pilot holes, carrier scrap, and possible cost-down options.
Does scrap value reduce the stamping price?
Sometimes. The quote should state whether scrap value is credited, retained by the पुरवठादार, or already considered in the piece price.
Can changing feed direction reduce scrap?
It can, but feed direction may also affect grain direction, burr side, bend quality, cosmetic orientation, and carrier strength.