Ejector Blades — With Engraving

Yes — dual engraving (date code + cavity number) is available for blades with a minimum tip width of 6mm. The date code insert occupies one side of the tip face, while the cavity number is laser-engraved on the opposite side. For blades narrower than 6mm, only one engraving type can be accommodated per blade. In multi-cavity molds requiring both markings, the common solution is to use the blade for cavity number (permanent) and a separate round ejector pin with a date code insert nearby. Dual-engraving adds 2–3 days to lead time beyond standard engraving.

Minimum blade width for legible engraving depends on the engraving type: (1) Cavity number (laser-engraved): minimum 2mm width for single-digit numbers, 3mm for two-digit, 4mm for three-digit. Character height scales with blade width — typically 60–70% of the blade width. (2) Date code insert: minimum 5mm width for standard insert size. (3) Custom text/logo: minimum 4mm width for up to 3 characters, 6mm for up to 6 characters. Below these minimums, the characters become too small for reliable reading on the molded part, especially after 50,000+ cycles of wear.

Laser-engraved cavity numbers reduce the effective ejection contact area by approximately 5–10% (the engraved channels are recessed, not load-bearing). This is negligible for most applications. Date code inserts reduce the contact area by approximately 15–25% because the insert pocket displaces material from the tip face. For thin-wall parts or parts with high ejection resistance, this reduced contact area can cause localized stress marks around the engraving — compensate by increasing the blade width by one size (e.g., 4mm instead of 3mm) or by adding ejection support from adjacent round pins. The engraving recess depth (0.05–0.10mm) does leave a corresponding raised mark on the molded part, which is intentional for traceability.