Quality Control
Quality is controlled throughout the manufacturing process — from drawing review and first-piece inspection to in-process verification and final inspection.
Quality Control Throughout Production
01 Drawing & Requirement Review
-
Customer drawings, materials, tolerances, performance requirements, and critical characteristics are reviewed before production begins.
02 Raw Material Verification
-
Material specifications and relevant documentation are checked according to project requirements before material enters production.
03 First-Piece Inspection
-
The first production samples are inspected for key dimensions, geometry, and functional requirements before batch production continues.
04 In-Process Inspection
-
Critical dimensions and performance parameters are monitored during production to identify deviations before they affect the full batch.
05 Performance Testing
-
Depending on the product, spring force, torque, fit, fatigue performance, or other functional characteristics can be verified.
06 Final Inspection
-
Finished parts are checked against approved requirements before packaging, with inspection records prepared when required.
In-Process Control
Key characteristics monitored during production
Drawing-Based Inspection
Customer specifications as the inspection basis
Final Verification
Inspection before packing and shipment
How We Verify Quality
Different products require different quality checks. We select inspection methods according to customer drawings, critical characteristics, and application requirements.
01 Dimensional Inspection
Key dimensions are checked against approved drawings using appropriate measuring tools according to the size, geometry, and tolerance requirements of each part.
Typical Checks
-
Wire diameter
-
Outside / inside diameter
-
Free length
-
Thickness
-
Bend dimensions
-
Angles and spacing
02 Spring Performance Verification
Spring performance is verified according to customer requirements, with load values checked at specified working heights or positions to confirm that the spring meets its intended functional requirements.
Typical Checks
-
Spring load
-
Working height
-
Compression / extension position
-
Free length
-
Performance consistency
_edited.jpg)
03 Geometry & Form Inspection
For torsion springs and custom wire forms, critical geometry is checked against drawings or approved samples to verify formed profiles, leg positions, angles, and other application-related features.
Typical Checks
-
Leg angle
-
Hook position
-
Bend geometry
-
Formed profile
-
Relative position
-
Overall shape
04 Surface & Appearance Inspection
Finished parts are visually inspected for surface condition, deformation, scratches, coating or plating appearance, and other visible defects before final approval.
Typical Checks
-
Scratches
-
Deformation
-
Plating / coating appearance
-
Surface defects
-
Color consistency
-
Burrs
05 Corrosion Resistance Testing
Salt spray testing is used to evaluate the corrosion resistance of springs, stamped parts, and other metal components with plated, coated, or treated surfaces. Test conditions and duration are selected according to customer requirements or applicable project specifications.
Typical Checks
-
Zinc-plated parts
-
Nickel-plated parts
-
Coated components
-
Corrosion resistance
-
Surface protection performance
-
Specified salt spray duration
At JIALUN, quality control is supported by clear production and inspection records. Key information such as material documentation, first-piece and in-process inspection results, product test data, and applicable compliance documents can be retained or provided according to project requirements. This documented approach helps our team review quality issues efficiently and gives customers clearer visibility into the manufacturing and inspection process.
Quality Documentation & Traceability
Material Records · Inspection Reports · Test Results · Compliance Documentation
