FAQ

Frequently Asked Questions

Find answers to common questions about precision CNC machining, injection molding, medical device parts, automotive components, drawing file formats, our Thailand factory, and delivery timelines.

🏥Medical Device Manufacturing

What precision levels can you achieve for medical device components?
We hold CNC machining tolerances down to ±0.005 mm and injection molding tolerances to ±0.05 mm. Our medical parts — including microplates, PCR plates, surgical instrument housings, and diagnostic device components — are manufactured in ISO 13485-certified processes with full dimensional inspection reports.
Do you provide material certifications and biocompatibility documentation?
Yes. We supply material certificates (EN 10204 3.1), RoHS/REACH compliance reports, and can coordinate third-party biocompatibility testing (USP Class VI, ISO 10993) through qualified labs upon request.
What cleanroom capabilities do you have for medical parts?
Our Suzhou facility offers ISO Class 8 (Class 100,000) cleanroom packaging for medical components. Assembly and inspection can be performed under controlled conditions to meet your quality requirements.
Can you handle small-batch medical prototyping?
Absolutely. We support rapid prototyping from 1 piece for CNC machined parts and low-volume injection molding with soft tooling. Typical prototype lead time is 5–7 business days.

🚗Automotive Parts Manufacturing

Are your automotive parts processes IATF 16949 compliant?
Our quality management system follows IATF 16949 principles. We provide PPAP (Production Part Approval Process) documentation including dimensional reports, material certs, and process flow charts for automotive customers.
What automotive components do you commonly manufacture?
We produce EV battery housing, motor end caps, transmission components, sensor housings, fluid system connectors, and interior trim parts. Materials include aluminum alloys (6061-T6, 7075), engineering plastics (PA66+GF, PBT, PPS), and stainless steels.
Can you support APQP and phased automotive project launches?
Yes. We follow the APQP framework with design review, DFMEA, process validation, and run-at-rate capability studies. Our engineering team can work with your team from prototype through mass production.

📐Drawing & File Formats

What drawing file formats do you accept for RFQ?
We accept 2D drawings in PDF, DWG, and DXF formats, and 3D models in STEP/STP, IGES/IGS formats. For quick reference, you can also send JPG, PNG, or GIF images of your parts. Compressed archives (ZIP, RAR) are welcome for multi-file submissions.
Do I need to provide both 2D drawings and 3D models?
3D models (STEP/IGES) are preferred as they allow us to directly program CNC toolpaths and mold designs. 2D drawings with critical tolerances and surface finish callouts are helpful for quality inspection. If you only have one format, we can usually work with it.
What if my drawing is in a proprietary CAD format?
Please export to STEP (.stp/.step) or IGES (.igs/.iges) — these are universal exchange formats supported by all major CAD systems (SolidWorks, CATIA, NX, Creo, etc.). If you need help converting, our engineering team can assist.
How do you ensure drawing confidentiality?
All files submitted through our RFQ system are encrypted in transit (HTTPS), stored on secure servers, and retained for 90 days by default. We sign NDAs upon request and never share customer drawings with third parties.

🇹🇭Thailand Factory

Why does Combition have a factory in Thailand?
Our Thailand factory serves ASEAN and global customers who need regional supply chain diversification. It provides tariff advantages for exports to certain markets and reduces lead times for Southeast Asian customers.
Is the Thailand factory quality standard the same as China?
Yes. The Thailand facility follows the same ISO 13485 quality system, uses identical CNC equipment and inspection instruments, and is staffed by engineers trained at our Suzhou headquarters. Quality reports and certifications are equivalent across both sites.
Can I choose which factory produces my parts?
Absolutely. We can assign your project to China (Shanghai/Suzhou) or Thailand based on your preference, target market, tariff considerations, or logistics optimization. Some customers split production between both sites for risk mitigation.

📦Delivery & Lead Time

What is the typical lead time for CNC machining prototypes?
Standard CNC machining prototypes ship within 5–7 business days after drawing confirmation. Urgent orders can be completed in 3–5 days with expedited scheduling.
How long does injection mold tooling take?
Soft tooling (prototype molds): 2–3 weeks. Hard production tooling (steel molds): 4–8 weeks depending on complexity. First articles from production molds ship within 1–2 weeks after mold completion.
What is the lead time for mass production runs?
Mass production typically takes 2–4 weeks after tooling is ready, depending on order quantity and post-processing requirements (anodizing, plating, assembly). We maintain safety stock for repeat orders to ensure continuous supply.
Do you offer international shipping?
Yes. We ship worldwide via DHL, FedEx, UPS for express (3–5 days), and sea freight for large orders (15–30 days). Our Thailand factory offers shorter transit to ASEAN countries. FOB Shanghai, FOB Shenzhen, and EXW terms are all available.

🔩Materials & Certifications

What materials can you work with for CNC machining and injection molding?
For CNC machining, we process aluminum alloys (6061-T6, 7075), stainless steels (303, 304, 316L), brass, copper, titanium, and engineering plastics (PEEK, POM, PTFE, Nylon). For injection molding, we handle PP, ABS, PC, PA66/PA66+GF, PBT, PPS, POM, PMMA, TPE/TPU and more. Material datasheets are available upon request.
What certifications does your quality system hold?
We are certified to ISO 9001 (quality management), ISO 13485 (medical devices), and IATF 16949 (automotive). Our facility also holds CE marking capability. We hold 30+ utility model and invention patents related to precision manufacturing processes.
Can you provide RoHS, REACH, or FDA-compliant materials?
Yes. We routinely source RoHS and REACH-compliant raw materials and can supply full compliance documentation. For medical and food-contact applications, we can coordinate FDA-grade material sourcing and third-party biocompatibility testing (USP Class VI, ISO 10993).
Do you supply material test reports with each shipment?
Yes. Every shipment can be accompanied by material certificates (EN 10204 3.1), dimensional inspection reports, and surface treatment certificates when applicable. First Article Inspection (FAI) reports per AS9102 are available for aerospace and automotive projects.

⚙️Customization & OEM Process

What is the typical OEM customization workflow?
Our standard process: (1) Receive your drawings or samples → (2) DFM review and quotation within 24–48 hours → (3) Prototype/sample approval → (4) Tooling or program setup → (5) Pilot run and inspection → (6) Mass production → (7) QC, packaging, and shipping. A dedicated project manager coordinates each stage.
Is there a minimum order quantity (MOQ)?
We support flexible MOQs. CNC machining has no minimum — even 1 piece is accepted for prototyping. Injection molding MOQ depends on tooling: soft tooling allows runs from 50 pieces; production tooling is most economical at 500+ pieces. We discuss the best approach for your volume during quotation.
Can you assemble components or provide finished products?
Yes. Beyond single-part manufacturing, we offer sub-assembly and full product assembly including ultrasonic welding, vibration welding, screw fastening, pad printing, laser marking, and custom packaging. We can ship finished products ready for end-user delivery.
How do you handle design modifications during a project?
We use a structured ECN (Engineering Change Notice) process. Any design change is documented, cost- and timeline-impact assessed, and submitted for your written approval before implementation. Revision history is maintained throughout the product lifecycle.

🛡️Quality Assurance & After-Sales

What inspection equipment do you use?
Our inspection lab is equipped with CMM (Coordinate Measuring Machine), optical comparators, surface roughness testers, hardness testers, salt spray test chambers, and tensile testing machines. Critical dimensions are 100% inspected for automotive and medical parts per control plans.
What happens if I receive defective parts?
We maintain a zero-defect target with full traceability. In the rare event of a quality issue, we initiate an 8D corrective action process within 24 hours: root cause analysis, containment, corrective action, and preventive measures. Replacement parts are shipped at our expense if the defect is confirmed.
Do you offer ongoing quality support for repeat orders?
Yes. For repeat customers, we maintain dedicated quality files including historical inspection data, SPC (Statistical Process Control) charts, and improvement logs. Our project managers conduct quarterly reviews to identify optimization opportunities and cost-reduction suggestions.
How long do you retain production records and samples?
Production records, inspection reports, and material certificates are retained for a minimum of 5 years. Golden samples are kept for 1 year after the last production run for reference. All records are available for customer audit upon request.

Still have questions?

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