PROCUREMENT · September 6, 2026 · 7 MIN READ

Drawing Review Before an RFQ: Twelve Things a Forging Supplier Needs From You

Most quotation delays are not commercial, they are informational. A drawing that omits the material standard, the heat treatment condition, the datum scheme and the inspection stage will generate three rounds of questions and a 20–30 % price spread between suppliers who guessed differently. The twelve-item checklist below is the shortest path to a quote you can compare.

WHERE THIS APPLIES AT FORGEPRESS CHINA

ForgePress China returns a manufacturability note against your drawing within three working days, listing every assumption made before quoting. Capacity: HKM3 hot-die forging line 1,000–5,000 t, part weight 0.1–500 kg, maximum envelope 1,200 × 800 mm, as-forged to ISO 8062 class C with critical dimensions machined to ±0.2 mm, process control to ISO 9001, first article 4–8 weeks from die design release.

KEY NUMBERS

Price spread between suppliers quoting the same part with different assumptions: typically 20–30 %.
A drawing without a material standard edition cannot be quoted precisely — GB, ASTM and JIS limits differ.
Missing datum scheme is the most common cause of first-article rejection.
A 3D model plus a 2D drawing marked "for reference" is the combination that produces the fewest disputes.

Material and condition

Grade with the standard edition: 42CrMo per GB/T 3077, not just "42CrMo".
Delivery condition: as-forged, normalized, quenched and tempered.
Hardness range with the test scale and location: 285–321 HB, measured 5 mm below the surface.
Any restriction on mill origin or certificate type (EN 10204 3.1 is the common requirement).

Geometry and tolerance

As-forged tolerance class, stated explicitly — DIN 7526 grade F, or your own table.
Datum definition on machined features, not drafted walls.
Which surfaces are machined and what the machining allowance is.
Whether the 3D model or the 2D drawing governs in a conflict — this single line prevents most disputes.

Process and inspection

Heat treatment after forging, with the specification: hardness, case depth, or microstructure.
Surface treatment: shot blast, phosphating, painting, with the standard.
Inspection stage for each callout: as-forged, after machining, or after heat treatment.
Acceptance documentation: material certificate, dimensional report, first-article report, PPAP if automotive.

The four items that most often go missing

The material standard edition. Without it, a supplier may quote GB 42CrMo while you expect ASTM A29 4140, and the price and the certificate will both differ.

The datum scheme. First-article rejection on a forging is more often a datum disagreement than a machining error, and it is expensive to resolve after the die is cut.

The inspection stage. If a drawing carries a tight flatness callout with no note saying "after machining", the supplier must either machine the part or refuse — and the quote will show which choice they made, in a way you may not notice.

The annual volume and the batch size. Die cost amortisation dominates the piece price below about 2,000 pieces, so a quote for 500 and a quote for 50,000 are not comparable even for the same drawing.

What a good RFQ pack contains

Item	Why it matters	Common omission
2D drawing, fully toleranced	Governs acceptance	General tolerance block left blank
3D model (STEP)	Drives die design	Sent as IGES with gaps
Material standard + edition	Sets certificate and price	Grade name only
Heat treatment spec	Adds a process step and cost	Assumed to be included
Annual volume + batch size	Sets die amortisation	Only one quantity quoted
Inspection and documentation	Sets the QA cost	Not mentioned
Target price and delivery	Filters the supplier list	Left to the supplier

A complete pack typically reduces quotation turnaround from two weeks to three days and narrows the price spread from 30 % to under 10 %.

Frequently asked questions

Should the 3D model or the 2D drawing govern?

State it explicitly on the drawing, because the two will disagree somewhere. The common convention is that the 2D drawing governs dimensions and tolerances and the 3D model governs the free-form surfaces, with any conflict reported before manufacture.

What material certificate should I ask for?

EN 10204 3.1 for most industrial work: a mill certificate with the actual test results for the heat, issued by the mill and traceable to the batch. Type 2.2 is a statement of compliance without test values, and it is not sufficient for a structural or pressure application.

How much does die cost affect the piece price?

Below about 2,000 pieces it dominates. A USD 4,000 die amortised over 500 pieces adds USD 8 per part; over 50,000 pieces it adds USD 0.08. That is why comparing quotes at different volumes is meaningless.