Short answer: In a customer-supplied coil or toll stamping RFQ, the buyer owns the metal and the stamper quotes conversion work. The RFQ must define receiving checks, certificate matching, lot segregation, storage, authorized loss, scrap ownership, leftover-coil return, quality responsibility, shortage response, packaging, and inventory reporting. Without those rules, a low conversion price can hide material exposure and production-stop risk.
Customer-supplied material changes the quote boundary. The drawing controls the finished component, while the commercial scope follows each coil through receipt, production, scrap disposition, and return. Use the stamping quote comparison guide for general quote scope; this page focuses on buyer-owned coil.
Before requesting a toll stamping quote, decide whether the stamper receives production coils, arranges buyer-funded slitting, or calls buyer-owned inventory. Send that model with the drawing through the RFQ form so storage, handling, and reporting are defined.
Define the conversion-only scope
A conversion quote should define the stamper’s responsibility for unloading, receiving inspection, storage, coil handling, setup, stamping, secondary operations, inspection, packing, inventory reporting, and shipment. Mark slitting, freight, outside finishing, special testing, and return transportation as included, excluded, or buyer-arranged.
| RFQ subject | Decision to document | Useful evidence |
|---|---|---|
| Receiving | Appointment rules, unloading party, count or weight check, and damage notification window. | Packing list, coil tag, receiving record, and photos when damage is visible. |
| Material identity | Which purchase order, certificate, heat, lot, and coil number must remain linked. | Mill certificate or service-center certificate matched to physical labels. |
| Inventory | Ownership, segregation method, reporting frequency, aging rule, and reconciliation basis. | Opening weight, issued weight, scrap, remnants, finished quantity, and closing balance. |
| Disposition | Who may approve scrap sale, remnant return, rework, substitution, or disposal. | Written authorization and a transaction record tied to the source lot. |
Receiving and material certificate control
The RFQ should state what is verified at receipt: coil count, weight, coil number, grade, temper, thickness, width, coating or finish, heat or lot number, packaging condition, edge damage, rust, and contamination. Define the sampling basis and whether measurements are informational or acceptance criteria.
Certificate review should match the document to the physical coil, not merely confirm that a PDF arrived. Define the action for missing tags, unreadable labels, conflicting heat numbers, or certificate values outside the purchase specification. Material on hold should remain identifiable and unavailable for production until an authorized person releases it. The certificate mismatch and receiving hold guide provides a useful exception workflow.
Keep buyer-owned lots separated and stored correctly
Lot segregation needs a physical and digital method. The RFQ can require a unique inventory record for each coil, durable status labels, separated locations, and controlled transfers to the press. If coils from different heats may be combined in one finished lot, say so explicitly; otherwise require source-coil traceability through production and packing. See the lot traceability guide for finished-lot planning.
Storage terms should address moisture, edge protection, stacking, handling equipment, packaging removal, corrosion prevention, and any material-specific storage limit. Agree how dormant or obsolete stock is reported. For ownership and inventory logic, compare the VMI and consignment inventory guide.
Set rules for loss, scrap, and leftover coil
Do not use one vague “scrap allowance.” Separate strip skeleton and edge trim from setup pieces, coil tails, samples, rejects, damaged material, and unplanned loss. Define the reconciliation basis, reporting interval, and permitted inventory variance.
Scrap ownership is a commercial term. The buyer may retain title, authorize the stamper to sell scrap, receive a documented credit, or ask for physical return. The RFQ should cover sale authorization, segregation by alloy, weighing records, freight, and disposal of contaminated material. For calculation context, use the coil yield and scrap rate guide.
Define a usable remnant: minimum remaining weight or length, acceptable coil condition, label requirements, protective wrapping, and return timing. Tiny remnants can cost more to identify and ship than they are worth, so the disposition threshold should be agreed before production.
Divide quality responsibility without gaps
Customer ownership does not remove process responsibility, and receiving inspection does not transfer responsibility for latent material defects. Separate buyer responsibility for specified material and documents from stamper responsibility for custody, handling, processing, inspection, and preservation.
Define how a suspected material defect is contained and investigated. Evidence may include affected coil identity, press observations, samples, measurements, photos, and remaining stock status. No substitute grade, temper, thickness, coating, or alternate lot should enter production without the agreed approval path. Link the decision process to the material substitution approval guide and stamped parts quality agreement checklist.
Plan for short coils, shortages, and line stops
A conversion-only RFQ should say what happens when delivered weight cannot support the release quantity, a coil is damaged, yield is worse than the approved assumption, or inventory records do not reconcile. Define the notification threshold, who can stop the run, whether partial quantities may ship, and who decides between replacement material, schedule change, or controlled use of another lot.
Include contacts for replenishment and urgent escalation. Negotiate responsibility for downtime, premium freight, rescheduling, and unfinished orders. Recovery timing depends on the material issue and production status and should follow a coil and schedule review.
Preserve coil identity through packaging
Finished packaging should carry the part number, revision, quantity, production lot, and source coil reference. Specify pack quantity, container, surface protection, separators, orientation, label, certificate packet, and partial-container rules. Use the packaging and shipping guide without losing the customer-supplied material link.
Customer-supplied coil RFQ inputs
- Controlled 2D drawing, available 3D model, revision, units, and critical features.
- Material grade, specification, temper, thickness, width, coating, finish, and approved source.
- Coil dimensions, weight range, core details, winding direction, tags, and protective packaging.
- Certificate type, required chemistry or mechanical data, and document-to-coil matching rule.
- Annual demand, release quantity, forecast, shipment schedule, and expected material arrival dates.
- Receiving checks, hold authority, lot segregation, storage conditions, and inventory report format.
- Expected yield basis, authorized loss categories, scrap ownership, credit method, and audit evidence.
- Remnant definition, return or disposal instructions, packaging, freight, and reconciliation timing.
- Quality responsibility, nonconformance workflow, substitution approval, and shortage escalation contacts.
- Finished-part inspection, labeling, lot traceability, packing, certificate, and delivery requirements.
Use the metal stamping RFQ checklist for the part and tooling package, then add the material-control terms above. Submit drawings, the coil specification, forecast, and proposed responsibility matrix through the Kontaktseite for a conversion-only scope review.
FAQ: customer-supplied coil stamping
What is toll stamping with customer-supplied coil?
Toll stamping is an arrangement in which the buyer supplies or owns the coil and the stamper charges for agreed conversion, handling, inspection, packaging, and related services.
Who owns scrap in a conversion-only stamping agreement?
Scrap ownership must be stated in the agreement. The buyer may retain title, authorize sale with a documented credit, request return, or approve another disposition method.
Does receiving a material certificate make the stamper responsible for material quality?
Not automatically. Certificate matching and receiving checks confirm agreed evidence, while responsibility for latent material defects and stamping process defects should be divided in writing.
What should happen if customer-supplied coil runs short?
The stamper should follow the agreed notification and containment plan, report available material and affected quantity, and obtain direction on partial production, replacement coil, or rescheduling.