Custom CNC Machining in China for Prototypes & Production

Send a 3D CAD model plus a controlled 2D drawing when the model does not fully define the part. Identify the part number and revision, units, material specification and condition, quantity or quantity breaks, critical dimensions and GD&T, threads, surface texture and finish, inspection and certificate requirements, and requested delivery date. State the governing drawing and acceptance standards. Complete, revision-matched files reduce clarification time and let engineering assess manufacturing and inspection risk before quoting.

Answer owner: PiPrecision Engineering Team

STEP or STP is preferred for solid 3D geometry, and PDF is preferred for the controlled 2D drawing. The upload system also accepts IGES or IGS, SLDPRT, STL, OBJ, 3MF, DXF, and DWG files, including ZIP or RAR packages. Tessellated formats such as STL, OBJ, and 3MF may be adequate for reference but are less suitable than solid CAD for precision machining. Provide a revision-matched 2D drawing for GD&T, threads, fits, surface-texture callouts, notes, and other requirements not reliably carried by the model.

Answer owner: PiPrecision Engineering Team

There is no single minimum order quantity for every project. PiPrecision can evaluate one-off prototypes as well as repeat production, but a practical minimum purchase or batch quantity may apply to raw material, special tooling, heat treatment, finishing, testing, or certification. Setup, programming, fixturing, inspection, and outside-process costs also affect the economical quantity. Request quantity breaks if you want to compare prototype and production pricing.

Answer owner: PiPrecision Engineering Team

Achievable tolerance depends on the feature type and size, datum scheme, material and condition, geometry, process sequence, surface finish, and measurement method. Individual size features may be reviewed for bilateral tolerances down to ±0.005 mm, but this is not a default general tolerance and does not describe position, profile, flatness, runout, or other geometric controls. Apply ISO 2768 or another general-tolerance standard only by explicit drawing reference. PiPrecision confirms each critical requirement and its inspection method during drawing review.

Answer owner: PiPrecision Engineering Team

Initial RFQ review targeted within 1 business day for complete submissions. Complete quotation timing depends on drawing complexity, materials, finishes, and inspection requirements. Production lead time begins from the agreed commercial trigger stated in the quotation, such as order acceptance, deposit, or final drawing approval, and depends on material, complexity, quantity, tooling, inspection, finishing, and capacity. Use only the committed dates on the quotation or order confirmation for planning.

Answer owner: PiPrecision Engineering Team

Project-specific options may include dimensional results, CMM reports for suitable features, first-article inspection, a certificate of conformity, and supplier or mill material certificates. These documents are not interchangeable: define the required format, governing standard or customer template, sampling level, traceability depth, and record language in the RFQ. AS9102 or another prescribed first-article format is supplied only when explicitly agreed. PiPrecision confirms document availability, scope, cost, and timing before production.

Answer owner: PiPrecision Quality Team