NDA and Factory Visit Before Sending Drawings to a China Casting Supplier

Yes. We sign the buyer's NDA, or our own, before reviewing drawings, 3D models or specifications. Send the NDA with your first email; we review it and return a signed copy, then you share the technical files and quantities for quotation.

Drawings stay with our engineering and quotation team, are used only to quote and produce your parts, and are not shared with other customers.

Many China-focused lawyers recommend an NNN (non-disclosure, non-use, non-circumvention) agreement written for Chinese law, in Chinese and English, with disputes heard in China. A standard US or EU NDA mainly covers confidentiality; an NNN also stops the supplier from using your design for itself or selling your part directly to your customers.

We are happy to sign either. If your legal team prepares an NNN, send it with the RFQ and we will review it in the same way. This is general information, not legal advice; ask your own counsel which form suits your parts.

Processes, materials, tolerances, finishes, certificates and, most importantly, which operations are done in-house and which are subcontracted. For HUAYUN that means silica sol investment casting, 4-axis and 5-axis CNC machining and polishing in our own facility in Xinyi, Jiangsu; stainless grades including 304, 316, 316L, CF8M, 17-4PH and 2205/2507 duplex; as-cast tolerances of CT4–CT6 and ±0.01 mm on machined features; Ra 1.6–3.2 µm as-cast; ISO 9001:2015 and EN 10204 3.1 material certificates.

Ask any supplier to name the operations it buys in (for example heat treatment, plating or PVD) so you know who controls each step.

Yes. Factory audit visits are welcome, before or after quotation. A useful visit covers wax injection and tree assembly, shell building, pouring, heat treatment and finishing, the CNC area, the inspection room and how material certificates are traced to each heat.

Tell us the date, the number of visitors, the parts you want to discuss and whether you want to see a part similar to yours in production, so the right engineers are available.

New Year's Day (1 January) is a public holiday with usually one to three days off; Chinese New Year falls on 6 February 2027 and is the long closure. The public Spring Festival holiday is roughly a week (about 5–12 February 2027 by current calendars), but many foundries stop for one to three weeks around it because workers travel home. The official 2027 holiday schedule is normally published by the State Council in November or December, sometimes with make-up working weekends.

For a visit on 2 January 2027 or any date close to a holiday, ask the supplier to confirm in writing that the factory is running and the team is on site. For orders, plan so that tooling and sampling are finished before mid-January, or expect production to resume about two to three weeks after Chinese New Year.

You send the drawings, quantities and requirements, and we reply with a DFM review and quotation, usually within 24 hours for straightforward parts. Useful files are STEP plus a 2D PDF with tolerances, the alloy and any heat treatment, finish (for example mirror polish, passivation or PVD), annual quantity and delivery terms.

Typical timing after approval: tooling 5–7 working days, samples 7–10 working days, production 3–5 weeks depending on quantity and finishing.