SKH51 Steel WPC Ejector Punches for Heavy Load with Dowel Holes

Injection mold tooling and heavy-duty pressing use ejector punches to drive parts from the cavity while keeping repeatable alignment under high cyclic loads. This SKH51 variant is designed for locating and workpiece support via an integrated dowel hole, which helps maintain center positioning during ejection.

• Automotive connector and bracket molds: The reinforced shank and single-stepped geometry improve load transfer when ejection forces fluctuate between cycles, reducing off-center wear around the locating interface.
• Appliance and metal-insert housings: When parts include press-fit inserts or require stable support during ejection, the dowel hole supports consistent centering and helps prevent wobble that can score cavity surfaces.
• Industrial covers with thick-wall runners/gates: Use the tip shape options (round, rectangle, oblong, double flatted round, radius rectangle) to match part geometry for controlled contact and improved ejection repeatability.

The WPC surface-treated SKH51 steel is suited to these applications where abrasive wear and cyclic loading are primary concerns.

SKH51 is a high-speed steel grade commonly selected for ejector components that must balance wear resistance with adequate toughness under repeated impacts. The product uses WPC surface treatment, intended to enhance resistance to cyclic wear at the tip and shank wear zones.

• Wear resistance: Improved surface performance via WPC helps limit material loss during long production runs.
• Toughness trade-off: As with many tool steels, increasing wear resistance can reduce impact tolerance compared with softer grades; proper sizing of the shank diameter (D) and correct alignment via the dowel hole helps mitigate peak stresses.
• Heat treatment state: Manufactured in a steel state suitable for tool use; follow supplier tooling practice for final finishing and any additional pre-/post-hardening operations specific to your production strategy.

Compared with general low-alloy ejector steels, SKH51 with WPC is typically chosen when abrasive wear, rubbing, and cyclic contact dominate component life.

To select the correct ejector punch dimensions, start by matching the tip contact geometry to the part geometry and then verify overall stack-up clearance using the shank and full-length variations.

• Tip dimensions (P and W): Choose P (tip dimension) within 5 ~ 18 mm, and select the W (tip dimension) based on your target envelope: 5 ~ 9.97, 6 ~ 12.97, 6 ~ 15.97, 6 ~ 19.97, or 6 ~ 24.97 depending on the chosen tip type.
• Shank diameter (D): Confirm load capacity and alignment by selecting D = 10, 13, 16, 20, or 25 mm.
• Length (L) and full length alteration (LC): Use the required stroke/space constraints with L = 60~130, 70~130, 60~100, or 70~100 mm and apply LC within the available ranges such as 47~129.9 to 129.9 depending on configuration.
• Tolerance & fit: When using the dowel hole for centering, ensure mating dowel/sleeve geometry in the ejector plate aligns with your assembly’s tolerance stack to prevent side loading.

Tip corner radius (R) options (0.15 ~ 4.98 up to 0.15 ~ 12.48 mm) can be selected to control stress concentration on the part.