CNC Machining — Frequently Asked Questions

Upload your CAD files (STEP, IGES, DWG, PDF) through our contact page or email them to redowan@gh-goldenhot.com. Include material, quantity, surface finish, and tolerance requirements. We respond within 24 hours.

There is no minimum order quantity for CNC machining. We accept single prototypes as readily as production runs of 10,000+ pieces.

We accept STEP (.stp/.step), IGES (.igs/.iges), SOLIDWORKS (.sldprt), DXF/DWG for 2D drawings, and PDF drawings. STEP is preferred for 3D models as it preserves tolerances and PMI data.

Standard quotes are returned within 24 hours. Complex multi-part assemblies or exotic materials may take 48 hours. For urgent RFQs, contact us directly via WhatsApp at +86 199 6042 4301.

Yes. We routinely sign NDAs before reviewing sensitive designs. Email us your NDA and we will sign and return it before accessing your files.

Prototypes (1–5 pieces): 3–7 working days. Small batches (6–50 pieces): 7–14 working days. Production runs (50+ pieces): 14–30 working days depending on complexity and quantity.

Yes. We offer 24–72 hour rush service for simple parts. Mark your RFQ as 'Rush' and we will prioritize scheduling. Rush orders may carry a 20–30% surcharge.

Yes. We ship worldwide via DHL, FedEx, UPS, and sea freight. Most orders to Europe and North America arrive in 3–5 business days by air.

We ship DDP (Delivered Duty Paid) by default for most countries — customs, duties, and brokerage are included in the price. DAP terms are available on request.

Standard tolerance follows ISO 2768-m (±0.1mm for most dimensions). High-precision machining achieves ±0.005mm. For tolerances tighter than ±0.01mm, please specify clearly on your drawing and we will confirm feasibility.

All parts undergo dimensional inspection before shipment. Precision parts receive CMM (Coordinate Measuring Machine) inspection with full inspection reports. First Article Inspection (FAI) reports are available on request.

We are ISO 9001:2015 (Quality Management System) and ISO 14001:2015 (Environmental Management System) certified. Certificates are available on request with any order.

Yes. Material test reports (MTR) and mill certificates are available for all metals. RoHS and REACH compliance documentation is available for applicable orders.

We machine aluminum (6061, 7075, 2024), stainless steel (303, 304, 316L), titanium (Grade 2, Grade 5), brass (C360, C260), copper (C101, C110), alloy steel (4140, 4340, H13), and engineering plastics (PEEK, POM/Delrin, Nylon, Polycarbonate). Other materials available on request.

Anodizing (Type II & III), powder coating, electroplating (nickel, chrome, zinc, gold), PVD coating, black oxide, passivation, bead blasting, polishing, and brush finishing. As-machined and deburr-only options are also available.

Yes. Anodizing is available in any RAL or Pantone color. Powder coating offers 200+ color options. Please specify the color code in your RFQ for an accurate quote.

Yes. For every order, we review your files for potential machining issues and provide free DFM feedback before production begins. Common issues we flag include thin walls, deep narrow pockets, unreachable features, and tolerance stack-ups.

In aluminum: 0.5mm walls are achievable for short spans; 0.8mm is more reliable for tall walls. In steel: 0.8–1mm minimum wall recommended. In plastics: 1mm minimum depending on material. We always flag marginal walls in our DFM review.

Yes. We offer reverse engineering from physical samples using CMM 3D scanning. We will create the CAD model and 2D drawing for your review and approval before any manufacturing begins.