Extended Range Ejector Punches (Metric, XNA Coating)

Extended-range ejector punches are used in injection mold tooling where parts must be released from deep cavities or long-reach gate regions without sticking. In deep automotive connector housings and interior lamp supports, the extended reach helps maintain stable ejection travel while the XNA coated sliding surface reduces friction during repeated cycles.

They are also suitable for medical device housings and precision electronics clips where consistent ejection force is needed to avoid surface marring. The XNA coating supports wear resistance at the ejector-to-bush interface, helping preserve alignment over the tool’s service life.

For large appliance housings and thick-walled casings, engineers can match the point length and selectable tip shapes (H, J, K, N, O, R, V, X, Y, Z) to local geometry and clearance constraints, improving contact reliability across varying ejection layouts.

The provided specification set identifies an XNA coated ejector punch variant, where the coating is the key functional improvement for mold reliability under high sliding contact. While the base steel grade and exact heat-treatment cycle are not specified in the available data, the intended performance target is lower coefficient of friction and improved resistance to adhesive and abrasive wear during continuous molding.

In practice, ejector punch steels are typically balanced between hardness (for wear resistance) and toughness (for impact and bending resistance). Higher surface hardness generally increases abrasion resistance but can reduce toughness if not properly heat treated; therefore, tools often use quenched & tempered or similar hardening approaches to maintain a stable combination of wear life and ductility.

• XNA coating: improves sliding wear resistance and reduces frictional galling risk at the guide interface.
• Trade-off: increased surface protection supports longer life, but proper clearance and alignment are still required to prevent bending stress.

Select an extended-range ejector punch by matching the required ejection travel and working tip geometry to the mold core/cavity layout. Use the fixed dimensions first: L1 (point length) = 25–30 mm and L (overall length) = 63–100 mm, ensuring the punch can reach the part contact zone while maintaining sufficient support length inside the ejector guide.

Then choose D (shank diameter) = 40, 45, 50, 56, or 63 mm to suit the guide bore/bushing sizing and to control lateral stiffness. Match the P and W dimensions to your layout’s spacing and clearance requirements, using the available ranges (P: 20–39.95, 25–44.95, 30–49.95, 35–55.95, 40–62.95 mm; W: 8–39.95, 9–44.95, 10–49.95, 11–55.95, 12–62.95 mm). The selectable R range (0.2–19.975, 0.2–22.475, 0.2–24.975, 0.2–27.975, 0.2–31.475 mm) supports adapting corner radii to reduce stress concentration and improve contact consistency.

• Tip shape: select H/J/K/N/O/R/V/X/Y/Z to fit local ejection contact geometry.
• Tolerance/fit: confirm guide and bushing clearance in your standard—XNA coating reduces friction but does not replace mechanical alignment requirements.