Sourcing
Most quality problems with imported machined parts come from requirements that were never written down. This guide walks through the RFQ package, first article approval, inspection documents, Incoterms and shipping.
To source CNC machined parts from China without quality surprises, send a complete RFQ package (3D model, toleranced 2D drawing, material, finish, quantities and inspection requirements), approve a first article with a dimensional report before production, require inspection reports and material certificates with each shipment, and agree on Incoterms and packaging in writing. Most quality problems come from information that was never written down, not from machine capability. The steps below make expectations explicit at each stage.
Quality issues on imported machined parts usually trace back to a small number of causes:
Each of these is preventable with documentation and a clear approval process.
A complete request for quotation gets you an accurate quote faster and prevents errors later.
If your design is confidential, send a non-disclosure agreement before or with the RFQ.
A good supplier will return engineering questions (sometimes called an EQ or DFM review) before quoting or before production: conflicting dimensions, unachievable tolerances, finish allowances, thread callouts and material availability. Treat these questions as a sign of diligence. A supplier that quotes a complex drawing with no questions at all may not have read it closely.
A first article inspection is a full dimensional and documentation check of the first part(s) produced with the production process. It verifies that the process can make the part to the drawing before the full batch is run.
A useful FAI package contains:
Aerospace suppliers often use the AS9102 format, and automotive programs may require PPAP. For most industrial parts, a ballooned drawing with a complete measurement report is sufficient.
For new parts, new suppliers or critical assemblies, yes. Order a small quantity of samples, test them in your assembly, and approve them in writing. Keep at least one approved sample as a "golden sample" for future reference, especially for cosmetic finishes and color.
Match the documentation to the risk of the part:
| Document | What it shows | When to require it |
|---|---|---|
| Dimensional inspection report | Measured values of critical or all dimensions | Every production shipment |
| CMM report | Coordinate measurement of complex features and GD&T | Tight positional tolerances, complex geometry |
| First article inspection (FAI) | Full report on first parts from a new or changed process | New parts, revisions, new suppliers |
| Material certificate (mill cert) | Chemical composition and mechanical properties of the raw material lot | Structural, safety-critical or regulated parts |
| Certificate of conformance (CoC) | Supplier statement that parts meet the drawing and PO | Most shipments |
| Finish/coating report | Coating thickness, adhesion or salt spray results | Functional coatings, outdoor parts |
Material certificates are often issued to EN 10204 type 3.1, which certifies test results for the specific lot.
For production lots, critical dimensions should be checked at 100% where practical, and other dimensions sampled. ISO 2859-1 (equivalent to ANSI/ASQ Z1.4) defines AQL sampling plans that let you inspect a statistically based sample size for a given lot size. State the AQL level in your purchase order or quality agreement if you need it. For high-risk parts, a third-party pre-shipment inspection is another option.
Incoterms 2020 define who pays for transport, insurance and duties and where risk transfers from seller to buyer. The most common options for machined parts:
| Incoterm | Seller's responsibility | Buyer's responsibility | Notes |
|---|---|---|---|
| EXW (Ex Works) | Makes goods available at the factory | Everything from pickup, including export clearance | Most work for the buyer |
| FCA (Free Carrier) | Delivers to buyer's carrier, export-cleared | Main transport, import | Suits air freight and express |
| FOB (Free On Board) | Delivers onto the vessel at the port, export-cleared | Ocean freight, insurance, import | Sea freight only |
| CIF (Cost, Insurance and Freight) | Pays freight and minimum insurance to destination port | Import clearance, duties, delivery | Sea freight only; risk passes at loading |
| DAP (Delivered at Place) | Delivers to named destination | Import clearance and duties | Common for express |
| DDP (Delivered Duty Paid) | Delivers to destination including duties and import clearance | Unloading | Least work for the buyer |
FOB and CIF are designed for sea and inland waterway transport. For air freight and express courier shipments, FCA, CPT, CIP, DAP or DDP are more appropriate, although FOB is still used informally.
The importer is responsible for classifying parts with the correct HS (Harmonized System) code and paying applicable duties. Tariff rates depend on the product classification, the destination country and current trade measures, and they change. Check current rates with your customs broker before committing to a landed cost. Provide the supplier with any specific invoice or labeling requirements in advance.
Axisform works under an ISO 9001 quality management system from its production base in Dongguan, Guangdong. Quotes are usually returned within 24 hours on business days. Each order typically includes first-article inspection, in-process checks and 100% inspection of critical dimensions before shipment; inspection reports and material certificates are available on request. Shipping is by DHL, FedEx, UPS, air or sea freight, with EXW, FOB, CIF or DDP terms by agreement. See about us, our projects, or send your RFQ package through contact.
Before sending the RFQ, it is worth checking your design against our DFM rules and tolerance guide.
Send a 3D model in STEP format and a 2D PDF drawing with tolerances, material, finish and quantities. The 3D model defines geometry, while the drawing defines tolerances, threads, surface finish and inspection requirements.
A first article inspection checks the first parts from a new process against every drawing requirement before production. A pre-shipment inspection checks a finished production lot, usually by sampling, before it leaves the factory.
It depends on how much logistics you want to manage. EXW and FOB give the buyer more control over freight; DDP gives the simplest delivery with duties included. For express and air shipments, FCA, DAP or DDP fit better than FOB or CIF.
Request a material certificate (mill certificate) for the raw material lot, often to EN 10204 3.1. For critical parts, you can also have a sample tested independently, for example by spectrometer analysis.
Send your drawing and an engineer will reply with DFM notes and a quote within 24 hours.
Request a quote
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