Quality control procedures
Published on Wednesday, 12. January 2005
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Content Guide：CNC Machining: Surface roughness Ra ≤0.8μm (precision molds: Ra ≤0.2μm); tool wear compensation frequency ≤500 pieces/tool.
Design Phase:
Drawing Review: Compliant with ISO 8015:2025 geometric tolerance specifications; critical dimension tolerances ≤±0.02mm.
Material Selection: Match material hardness (HRC 48-62) based on mold lifespan requirements; provide ISO 6892-1:2025 material certification.
Processing Stage:
CNC machining: Surface roughness Ra ≤0.8μm (precision molds: Ra ≤0.2μm); tool wear compensation frequency ≤500 pieces/tool.
Heat Treatment: Vacuum quenching hardness deviation ≤±1.5 HRC; tempering temperature fluctuation ≤±5℃ (compliant with AMS 2750F).
Surface Treatment: PVD coating thickness error ≤±0.3μm; coating adhesion ≥80N (tested per ASTM C1624).
Assembly & Debugging:
Mold clamping gap ≤0.03mm; slider friction coefficient ≤0.1 (after lubrication).
Trial runs ≥3 times; must pass ISO 20417:2025 stability test before mass production.
Inspection Item | Tool/Method | Acceptance Criteria | Frequency |
|---|---|---|---|
Dimensional Accuracy | CMM (Coordinate Measuring Machine) | Critical dimensions CPK ≥1.33 | Full inspection per batch |
Surface Hardness | Vickers Hardness Tester (HV 0.5) | Hardness within ±2% of nominal value | Sampling per heat treatment batch |
Coating Adhesion | Cross-Cut + Pull-Off Test | No peeling (ASTM D3359 Class 5B) | 1 per 100 pieces |
Mold Lifespan Verification | Cycle Counter + Metallography | No cracks/deformation before 500k cycles | First piece & annual recheck |
Defect Classification:
Category A (Critical): Dimension error >0.1mm, cracks, coating peeling → Immediate scrapping.
Category B (Major): Surface roughness超标, hardness deviation >3% → Rework + full inspection.
Category C (Minor): Non-critical surface scratches (depth <0>
Corrective Actions:
Root Cause Analysis: 8D report within 48 hours, including Fishbone Diagram and 5Why analysis.
Preventive Optimization: Update process parameter database; trigger ISO 9001:2025 internal audit.
Documentation Delivery:
Mandatory: Material certification, heat treatment curves, full-dimension inspection report, RoHS/SVHC compliance declaration.
Optional: CAE mold flow analysis report, DFMEA (Design Failure Mode Analysis).
On-Site Acceptance:
Functional Test: ≥99.5% yield rate in 100 consecutive productions.
Safety Requirements: Edge rounding (R≥0.2mm); grounding resistance ≤0.1Ω (for anti-static molds).
Notes:
All processes require IATF 16949:2025 automotive industry certification (for automotive molds);
Environmental requirements: Waste recycling rate ≥95%, compliant with EU 2025/EC Green Manufacturing Directive.
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