Tom Yang writes practical manufacturing guides for engineers and procurement teams sourcing drawing-based CNC parts. His work focuses on supplier evaluation, production planning, materials, tolerances, DFM, dimensional inspection, quality control and overseas sourcing risk.
Tom Yang 专注于 CNC 加工、海外供应商审核、材料与公差、DFM、质量控制以及从图纸到生产的制造流程内容，为海外工程和采购团队提供实用参考。
CNC machining may have no technical MOQ, but every order carries fixed engineering, programming, tooling, setup, inspection and administrative cost. For one to five parts, unit price is dominated by t
First protect production: identify the affected drawing revision and lot, stop use, segregate stock and define a verified sort. Then establish measurement agreement, disposition authority, root cause,
Select a finish from function first: substrate, corrosion exposure, wear, electrical contact, appearance, dimensional allowance and compliance. Then define color/texture samples, masking, rack marks,
EXW gives the buyer responsibility very early, FOB is suited to sea or inland-waterway shipments with the seller delivering on board at the named port, and DDP places the broadest delivery obligation
Choose 6061 when corrosion resistance, weldability, availability and cost dominate. Choose 7075 when higher strength-to-weight performance justifies greater material cost, lower weldability and more c
The most expensive drawings often contain unnecessary tight tolerances, deep pockets, tiny internal radii, thin walls, hard-to-reach features, excessive setups, nonstandard threads, cosmetic requireme
Use layered protection: disclose only what is necessary, verify the recipient, define permitted use and subcontracting, control file access and revisions, apply China-appropriate contracts, and retain
Lead time is the sum of engineering review, material, programming and tooling, machining, external finishing, inspection, packing, export handoff, freight and import clearance. Ask for a milestone sch
A certificate is useful only when it connects to the purchased stock and finished part. Require the specification, grade, heat or lot number, chemical/mechanical results, issuer, purchase record, stoc
A machine’s best possible accuracy is not the same as a stable production tolerance. Real capability depends on feature size, geometry, material, setup count, temperature, tool wear, datum strategy, m
Learn how to verify whether a Chinese CNC supplier is a factory or trading company using legal identity, live process evidence, technical depth and payment checks.
A practical 12-point CNC supplier audit covering legal identity, machine ownership, drawing control, material traceability, inspection capability, capacity and trial-order evidence.