Technical Guide4 min read

How to Regrind Stepped Ejector Pins Without Losing Engraving

Key Takeaway: Laser-engraved cavity numbers survive 1–2 re-grinds (≤0.1mm total removal). Date code inserts survive 5+ re-grinds (1.5–2.0mm pocket depth). After each re-grind, verify engraving legibility and adjust ejector stroke.

Re-Grind Limits by Engraving Type

Engraving Type	Original Depth	Max Re-Grind Removal	Re-Grinds Possible
Laser cavity number	0.05–0.10mm	0.10mm total	1–2
Laser custom text	0.05–0.10mm	0.10mm total	1–2
Date code insert	1.5–2.0mm pocket	1.0mm total	5–10

Re-Grinding Procedure for Stepped Pins

Critical: re-grind only the tip face (D1 surface), never the shaft (D2). Grinding the shaft changes the step transition location, which alters the ejection stroke geometry. After re-grinding, the overall pin length decreases — compensate by adding a shim under the pin head or adjusting the ejector plate stroke. Maximum total re-grind removal before pin replacement: 0.5mm for stepped pins (the step transition fillet radius must be preserved).

Frequently Asked Questions

Can re-engraving be done on a re-ground pin?+

Yes — laser re-engraving costs $5–10 per pin and takes 1–2 business days. The pin must be removed from the mold and shipped to the engraving service. For time-critical production, keep pre-engraved spare pins in stock.

Is re-grinding cost-effective vs replacement?+

Re-grinding costs $2–5 per pin vs $15–40 for a new engraved stepped pin. Re-grinding is cost-effective for the first 1–2 cycles. Beyond that, the cumulative re-grind cost plus increasing risk of engraving loss makes replacement more economical.