How do I start ordering cNC machining and metal parts from a Chinese factory?
Confidence 4/5 Established practice
A workable first order follows the same sequence in every category: fix the specification in writing including tolerance and finish; decide the quantity against the minimum above; get a physical sample approved before any mass production; agree tooling ownership and payment terms in writing; arrange inspection before the balance is paid; and confirm the HS code and the destination labelling requirements before the goods ship rather than after. For cNC machining and metal parts the two details that most often delay a first order are specifying a tolerance the part does not need. Tightening from ±0.1 mm to ±0.02 mm can multiply cost and asking for "stainless steel" without a grade. 304 and 316 differ in corrosion performance and price.
Sources
- CNC machining cost drivers and volume crossover — Industry practice; consistent with published machining service pricing
- Iron and steel article classification — World Customs Organization HS nomenclature
- Section 232 steel and aluminium derivative tariffs — US Department of Commerce
What goes wrong with cNC machining and metal parts
- Specifying a tolerance the part does not need. Tightening from ±0.1 mm to ±0.02 mm can multiply cost.
- Asking for "stainless steel" without a grade. 304 and 316 differ in corrosion performance and price.
- Surface finish defined only by adjective. Ra values or a physical sample are needed.
- Ignoring deburring and passivation, which are separate operations and often quoted separately.
- Assuming a machining quote scales linearly to volume; it does not, and the crossover to casting arrives sooner than expected.
Related questions people ask
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