Tapered Head Ejector Punches - RP Coating

Tapered-head ejector punches are used to drive stripped parts from cavity inserts in precision injection mold tooling, especially where high-cycle ejection can cause abrasive wear at the tip.

In automotive connector and sensor housing molds, tapered geometry helps maintain consistent ejection engagement across varying part thicknesses, while the RP coating system is suited for repeated punch strokes that otherwise shorten service life.

For consumer electronics and appliance enclosure tooling, these punches support progressive and multi-station operations where downtime for tip rework is costly; the RP coating improves wear resistance and coating adhesion during continuous punching cycles.

• RP coating + alpha treatment supports stable performance under repeated contact and sliding
• Commonly integrated as ejector elements in progressive tooling requiring reliable action
• Best fit when conventional coatings show adhesion or wear limitations

This variant uses powdered high-speed steel, equivalent to SKH51 (AISI M2 equivalent). High-speed steel provides a balance of hardness, wear resistance, and toughness for punching and sliding contact at the ejector tip.

The RP (Al-Cr based) coating with alpha treatment is intended to improve both wear resistance and coating film adhesion under repeated punching. In service, coating systems typically trade maximum base-metal toughness for surface durability; with HSS, substrate toughness remains robust enough to reduce chipping risk.

• Hardness: HRC value not provided in the input data
• Wear resistance: enhanced by Al-Cr RP coating and alpha treatment
• Heat treatment state: specific tempering/nitriding condition not provided in the input data

If your application is dominated by impact/chipping rather than abrasion, compare with tougher substrate grades; if dominated by abrasion at the tip, this SKH51-equivalent base plus RP coating is typically preferred.

Select dimensions by matching the ejector punch’s shank and tip geometry to the mold’s ejector plate clearance and the part/core contact zone. The D (shank diameter) is available at 8, 10, 13, 16, 20, 25 mm, so choose the diameter that fits your guide/stripper and maintains proper alignment.

For stroke and packaging, use L = 60–100 mm and confirm that LC (full length alteration) = 37–99.9 mm provides the needed extension allowance in your ejector system design.

• Choose tip parameter set based on required contact size: P ranges from 3–7.99 up to 18–24.99 mm
• Choose PC (tip dimension alteration) based on the available variation set: 1.5–2.99, 3–5.99, 5–9.99, 6.5–12.99, 9–17.99 mm
• Confirm B (tip length) as either L or S depending on engagement depth

Tolerance/fit values are not provided in the input data; verify fit against your guide bushing clearance, and ensure tip dimensions do not interfere with cavity surfaces or ejector return travel.