Unexpected price hikes post-tooling or unfulfilled tolerance requirements often stem from incomplete initial technical RFQ packages. Structuring a clear, unambiguous technical request for quote is the first line of defense in overseas supplier management. This guide shows sourcing engineers how to build a technical RFQ for China die casting sourcing that eliminates misunderstandings, with reference to ISO 8062-3, ASME Y14.5, ASTM B85, and ISO 9001:2015 quality system requirements.
Technical RFQ Package Checklist
| RFQ Element | Reference Standard | Why It Prevents Misunderstandings |
|---|---|---|
| 2D drawing with GD&T | ASME Y14.5 / ISO 1101 | Defines datums, position, flatness unambiguously |
| 3D CAD (STEP/IGES) | ISO 10303 | Removes interpretation gaps on complex geometry |
| Alloy specification | ASTM B85 / DIN 1725 (ADC12, A356) | Locks chemistry and mechanical property targets |
| Tolerance class | ISO 8062-3 CT4–CT9 | Aligns as-cast vs machined tolerance expectations |
| Leak & pressure test spec | Customer-defined (e.g., 0.2 MPa air) | Avoids re-testing disputes and hidden cost |
| Tooling terms | Steel grade, shot life, ownership | Prevents post-tooling price negotiations |
| Quality agreement | ISO 9001 / IATF 16949, Cpk ≥ 1.33 | Sets PPAP, inspection, and PPM expectations |
1. Complete 2D GD&T and Datum Callouts
Providing 3D CAD models alone is insufficient. Critical functional dimensions, geometric tolerances (flatness, position, concentricity), and primary machining datums must be clearly defined on 2D engineering drawings per ASME Y14.5 to ensure alignment between factory CMM inspection and your incoming quality control (IQC). Without GD&T, suppliers will interpret profile and position requirements differently — one of the most common sources of disputes in China sourcing.
A professional request for quotation also states the tolerance class per ISO 8062-3 for as-cast features (typically CT4–CT6 for HPDC, CT7–CT9 for gravity/LPDC) and requires capability evidence (Cpk ≥ 1.33) on critical dimensions. Specify the measurement method and the number of samples for first-article inspection, otherwise CMM program differences alone can create false non-conformances.
2. Explicit Leakage and Pressure Test Specifications
For pressure-tight housings, specify the exact test medium (air or water), test pressure (e.g., 0.2 MPa), allowable leak rate (cc/min), and designated seal surfaces. Clearly state whether vacuum impregnation is permissible in case of micro-porosity. A technical RFQ that leaves these parameters open invites the supplier to quote the cheapest interpretation, which often surfaces later as failed leak tests and costly re-negotiation.
3. Tooling Ownership and Amortization Terms
Explicitly define mold steel grades (e.g., SKD61/DH31), guaranteed tool life (number of shots), core pin spare parts provisioning, and clear ownership of intellectual property and physical tooling upon completion of payments. Include the expected die life in shots and the maintenance scope the price covers. These clauses turn a technical RFQ into a binding framework that prevents “tooling surprise” price increases after the first production order.
4. Quality Agreement, PPAP, and Inspection Standards
Attach the quality agreement to the technical RFQ: required certifications (ISO 9001:2015, IATF 16949 for automotive), PPAP level, sampling plan (AQL), and acceptable PPM targets. Specify the inspection equipment (CMM per ISO 10360, OES chemical verification per ASTM B85) and the format of the inspection report. When the quality system is defined before quoting, the supplier prices the work correctly and you avoid costly divergence during production.
5. Commercial Terms: Incoterms, Payment, and Lead Time
Finally, state Incoterms (EXW, FOB, CIF), payment milestones (e.g., 30/70 or 40/60 for tooling), target PPAP date, and serial production lead time. Include packaging and logistics expectations. A complete technical RFQ covers engineering, quality, and commercial dimensions so that the returned quotation is directly comparable across suppliers.
FAQ for Procurement & Production Technology Teams
Q1: What is the minimum content a technical RFQ for die casting must include?
A: 2D drawing with GD&T per ASME Y14.5, 3D STEP file, alloy specification per ASTM B85/DIN 1725, tolerance class per ISO 8062-3, leak test requirements, tooling terms (steel grade, shot life, ownership), and the quality agreement (ISO 9001, PPAP level, Cpk targets). Missing any of these invites misinterpretation.
Q2: How do I avoid unexpected tooling price increases from Chinese suppliers?
A: Lock the tooling scope in the technical RFQ: steel grade (e.g., SKD61), hardness range (44–52 HRC), guaranteed die life in shots, included spare parts, and design change rules. Require a fixed tooling price valid for 6–12 months and define the approval process for engineering changes.
Q3: Which tolerance standard should I reference in the RFQ?
A: Reference ISO 8062-3 for as-cast tolerance classes (CT4–CT6 HPDC, CT7–CT9 gravity/LPDC) plus ASME Y14.5 GD&T on the 2D drawing. Require Cpk ≥ 1.33 capability studies and specify CMM verification per ISO 10360 for critical dimensions.
Q4: How does X-Diecasting Tech support RFQ structuring?
A: With 20 years of die casting and mold engineering experience, our founder-led team reviews your drawings, drafts the complete technical RFQ package — including GD&T review, tolerance analysis, and quality agreement — and supports supplier evaluation. Contact our engineering team to have your RFQ package professionally structured before you send it to China.
A well-structured technical RFQ is the cheapest insurance in global sourcing: it aligns engineering intent, quality expectations, and commercial terms before a single quote is issued. By referencing ISO 8062-3, ASME Y14.5, ASTM B85, and ISO 9001, you make your requirements measurable and comparable across suppliers. For help building or reviewing your RFQ package, contact our engineering team.
About X-Diecasting Tech: Founded by an engineer with 20 years of die casting and mold design experience, X-Diecasting Tech provides aluminum die casting components, tooling, and process engineering support to global OEMs and tier suppliers. Our team applies ISO 9001-aligned quality systems and ASTM / DIN / ISO standards across every program we support.