1. Visual Inspection
Check for obvious defects on the surface:
Scratches, dents, and rust
Welding or cutting defects
Burrs or sharp edges
Paint or coating defects
Distortion or warping
Tools: Naked eye, magnifying glass, good lighting, surface comparators.
2. Dimensional Inspection
Verify that the part meets drawing dimensions and tolerances.
Flatness: Check with a surface plate and feeler gauges.
Thickness: Measure using a micrometer or ultrasonic thickness gauge.
Hole size and position: Use calipers, plug gauges, or a coordinate measuring machine (CMM).
Bend angles and radii: Check with a protractor, radius gauge, or angle gauge.
Overall dimensions: Use calipers, height gauge, or laser measuring tools.
Tools: Vernier caliper, micrometer, height gauge, CMM, laser scanner.
From sheet metal fabrication companies china – Xu Cheng Precision
3. Geometric Tolerance Inspection (GD&T)
Check form, orientation, and position tolerances per engineering drawings.
Flatness and parallelism → CMM or surface plate.
Perpendicularity and angularity → Dial indicators or CMM.
Profile and true position → Optical measuring systems or CMM.
Tools: CMM, laser tracker, optical comparator.
4. Fit and Assembly Check
Ensure parts fit properly in the assembly:
Test-fit with mating components or jigs.
Check alignment, hole positions, and clearance.
Tools: Assembly jigs, templates, gauges.
5. Surface Finish Inspection of china sheet metal parts
Verify smoothness and coating quality:
Surface roughness (Ra value) using a surface roughness tester.
Coating thickness using a coating thickness gauge.
Color or gloss consistency with color meters or gloss meters.
Tools: Surface roughness tester, coating thickness gauge, gloss meter.
6. Material and Structural Tests (if required)
Confirm material properties and internal quality:
Hardness test (Rockwell, Vickers, etc.)
Material composition analysis (XRF or spectrometer)
Non-destructive testing (NDT) for cracks or voids:
Dye penetrant test (PT)
Ultrasonic test (UT)
Magnetic particle inspection (MPI)
7. Documentation and Reporting
Record all inspection data:
Inspection report with pass/fail criteria
Photos for visual defects
CMM or gauge reports for dimensional data
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