How to Use Engraved Stepped Pins for Multi-Cavity Traceability
Key Takeaway: For multi-cavity molds, assign a unique cavity number to each cavity via engraved ejector pins. This enables per-cavity SPC tracking, defect source identification, and compliance with automotive PPAP and medical ISO 13485 requirements.
Cavity Numbering Systems
| System | Format | Best For |
|---|---|---|
| Sequential | 1, 2, 3... N | Standard molds, simple tracking |
| Row-Column | A1, A2, B1, B2... | Stack molds, multi-level layouts |
| Date+Cavity | 2607-01, 2607-02... | Automotive PPAP with lot tracking |
Pin Selection for Multi-Cavity Marking
In a 32-cavity mold, 32 uniquely engraved pins are needed. Key considerations:
- Pin diameter: ø3mm minimum for 1-digit numbers, ø4mm for 2-digit, ø5mm for 3-digit
- Placement: Choose a consistent location on each cavity — typically near the gate for easy correlation with fill simulation
- Spare pins: Order 2 spare sets (64 extra pins) for immediate replacement during maintenance
Compliance with AIAG automotive standards requires that cavity identification is visible on every production part without magnification.