DFMDraft, parting line, machining stockClosed die forging supplier checks before you accept an alternative
Use this desk to close open specification choices: DFM notes on draft and stock, GD&T that can actually be probed, material substitutions, and FAI/PPAP document lists. A closed die forging supplier remains the process owner; this page is a decision aid, not a factory capability sheet.
Send the open itemsDFMDraft, parting line, machining stock
GD&TDatums reachable after trim
FAICoupon from the production heat
PPAPLevel and included documentsBaseline closed-die route versus a proposed alternative
Use the table to record what must stay identical and what the buyer still has to decide. Numbers in the right column are questions, not shop promises.
| Decision | Keep on the baseline RFQ | Treat as a written alternative |
|---|---|---|
| Process | Closed-die impression, named press or hammer class if known | Open-die, casting, or fully machined billet |
| Material | Specified grade and melt documents | Substitute alloy with equal or documented properties |
| Heat treat | Anneal / quench / temper and hardness method | Skip or relocate heat treat without a new hardness window |
| Preform / flash | Stated preform yield and flash-land wear assumption for the lot size | A tighter preform that hides an early resink |
| Tolerance | As-forged versus machined features called out separately | Tighter callouts that force extra coining or 100% CMM |
| Inspection | FAI coupon from the same heat as production, CMM, NDT, hardness map as line items | Certificate of conformance only, or a cousin-heat coupon |
| Cost basis | Die, piece, inspect, freight, duties | Single blended unit price with hidden NRE |
Specification questions still open on most first briefs
Geometry
Mark them. As-forged Ra and draft differ from machined faces. Mixing them on one tolerance block creates disputes at FAI. Surface roughness examples such as Ra 1.6 μm as-forged versus a later machined face should be written, not assumed.
If the datum is later machined away, FAI needs an interim fixture or a relocated datum. Ask the plant before tool kickoff.
Commercial and documents
No. Stroke life depends on die steel, billet temperature, lubrication, and flash-land wear. Request the plant's assumption for this lot; do not copy a brochure MTBF.
Economy preference is a buyer cost stance, not a verified rating. If NADCAP heat treat or ISO 13485 melt traceability is required, an economy-only shortlist may simply be out of process.
Close the open items, then request factory quotes
List remaining specification choices and what must be verified before an alternative is accepted. Then request factory wholesale quotations on the surviving baseline, with coupon and QMS rules still attached to the closed die forging supplier that would run the dies.