Quality You Can Measure, Not Just Trust
At KUSLA, quality control is built into every stage of production — not added at the end. From incoming material checks to final dimensional reports, every part leaves our Suzhou facility with a documented quality record.
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Six-Stage Quality Control Framework
Problems caught early cost a fraction of problems caught late. Our QC framework intercepts defects at every transition in the production chain.
Drawing & DFM Review
Before a single chip is cut, our engineers review your CAD files and drawings for manufacturability.
- Tolerance feasibility check
- Surface finish achievability review
- Material suitability confirmation
- DFM feedback within 24 hrs
Incoming Material Inspection
Raw material is verified against mill certificates and tested before entering production.
- Material certifications on file
- Dimensional verification of stock
- Hardness / grade spot-checks
- Non-conforming material quarantined
In-Process QC (Every 2 Hours)
QC engineers conduct structured inspections at every machine every 2 hours — not only at shift changes.
- Critical dimensions measured per drawing
- On-site inspection system auto-alerts
- Out-of-spec parts quarantined immediately
- SPC data logged for trend analysis
Post-Machining CMM Inspection
Finished parts are measured on a Coordinate Measuring Machine to verify geometric accuracy against the nominal CAD model.
- GD&T verification (flatness, circularity, position)
- Thread verification with pin gauges
- Depth and bore measurement
- 2D optical scanning for complex profiles
Surface & Appearance Inspection
Visual and tactile inspection under standardized lighting confirms surface finish, coating quality, and cosmetic requirements.
- Ra/Rz roughness comparison gauges
- Anodize / plating color & adhesion
- Edge break & deburring confirmation
- Optical transmittance for clear parts
Final Inspection & Shipment Release
Every order undergoes a final hold-for-release review before packaging. No part ships without a signed-off inspection record.
- 100% dimensional check for prototypes
- AQL sampling for production runs
- Inspection report issued (on request)
- Packaging verified against damage risk
Five Instruments. One Standard: Accuracy.
Our inspection lab is equipped for dimensional, geometric, optical, and surface verification across all processes we offer.
Coordinate Measuring Machine (CMM)
3-axis contact measurement of geometric features, GD&T callouts, and complex freeform surfaces. Primary instrument for post-machining dimensional sign-off.
2D Optical Detector
Captures high-resolution images for non-contact dimensional verification. Particularly effective for thin-walled and fragile parts where contact probing risks distortion.
Pin Gauge & Gauge Block Set
Full range of go/no-go pin gauges and traceable gauge blocks for verifying bore diameters, thread fits, and establishing reference standards for in-process measurement.
Optical Transmittance Meter
Measures light transmission, haze, and clarity of optical components and clear enclosures. Critical for automotive lighting prototypes and acrylic machining projects.
Handheld 3D Laser Scanner
Captures full-surface geometry of complex parts in minutes. Used for first-article inspection, reverse engineering verification, and comparing scan data against the original CAD model.
Standard Tolerances by Process
Use this table as a starting point. If your drawing specifies tighter tolerances, discuss requirements with our engineers before ordering.
| Process | Standard Tolerance | Tight Tolerance | Surface Finish (Ra) | CMM Verified | Inspection Report |
|---|---|---|---|---|---|
| CNC Milling | ±0.05 mm | ±0.02 mm | 0.8 – 3.2 µm | ||
| CNC Turning | ±0.05 mm | ±0.01 mm | 0.4 – 1.6 µm | ||
| Sheet Metal | ±0.1 mm | ±0.05 mm | N/A (as-formed) | ||
| 3D Printing (SLA) | ±0.1 mm | ±0.05 mm | 1.6 – 6.3 µm | On request | On request |
| Urethane Casting | ±0.2 mm | ±0.1 mm | Mold-dependent | On request | On request |
| Injection Molding | ±0.05 mm | ±0.02 mm | 0.4 – 3.2 µm | ||
| Diamond Turning (SPDT) | ±0.005 mm | ±0.001 mm | <0.01 µm (Ra) |
Know Exactly What Left Our Factory
Every report is produced by our QC engineers — not auto-generated. Request one for any order and receive a structured document covering all critical features of your part.
Quality That Satisfies Global Brands
Our QC standards have earned the trust of tier-1 automotive suppliers, lighting manufacturers, and global engineering firms.
"The quality control at KUSLA has truly impressed me. From several collaborations, they have never disappointed in terms of quality. Whether it's precision machining or surface finishing, they consistently meet our specifications — and they back it up with data."
Common Quality Control Questions
Is KUSLA ISO 9001:2015 certified?
Yes. KUSLA holds GB/T9001-2016/ISO 9001:2015 certification. All production and inspection procedures are governed by this standard, and our certificate is available on request.
Do you provide a full dimensional inspection report?
Yes, on request for any order. The report covers all critical dimensions, thread specifications, tolerances, surface finish readings, and part appearance for every part produced.
How often are in-process inspections performed?
Our QC engineers conduct in-process inspections every 2 hours throughout active production — not only at shift changes. This catches deviations before they propagate across a batch.
What tolerances can KUSLA hold for CNC machined parts?
Standard CNC tolerances are ±0.05 mm. For tight-tolerance work we routinely hold ±0.02 mm. Select precision applications — including SPDT optical parts — can reach ±0.001 mm.
Can I get material certifications for my order?
Yes. Material mill certificates are available for most metallic materials including aluminum alloys, stainless steel, and titanium. Request this when placing your order.
How do you handle non-conforming parts?
Non-conforming parts are immediately quarantined, tagged, and reported to the production team. Root cause analysis is conducted and corrective action documented before the next production run continues.
Ready to Start Your Project?
Upload your CAD files and receive a quote with DFM feedback within 24 hours. Our engineers review every submission personally.
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