JIS Standard SKD61 Steel Stepped Ejector Sleeves

Stepped ejector sleeves are used inside injection mold tooling to guide knockout motion and maintain stable alignment between the ejector system and the moving parts. In automotive connector and sensor housings, the stepped geometry supports repeatable positioning during high-cycle ejecting, helping reduce side-loading on pins and improving part edge consistency.

For medical device housings and precision casings, this variant’s nitrided SKD61 surface targets wear resistance in environments where ejector movement must remain smooth over extended production runs. The built-in steps provide guided support at multiple contact zones, which helps maintain coaxial alignment under load.

In general electronics packaging molds, the JIS-standard compatibility and tight bore-to-shaft fit make it easier to integrate with die components and maintain proper tolerances for reliable core/cavity knockouts.

• Use when consistent ejector alignment is critical (e.g., connectors, casings).
• Prefer for long service life where abrasion and sliding wear dominate.
• Select based on shaft diameter range and step geometry to match the ejector assembly.

This stepped ejector sleeve is made from JIS SKD61 steel, a hot-work die steel commonly selected for molds requiring a balance of wear resistance and toughness. The provided description specifies a nitrided surface, which enhances surface hardness and improves resistance to scuffing and adhesive wear during repeated ejector sliding.

• Heat treatment state: nitrided surface for wear resistance (bulk behavior depends on the underlying SKD61 heat treatment used by the manufacturer).
• Wear resistance: improved by the nitrided layer, supporting long service life under frequent cycling.
• Toughness trade-off: hard surface layers can reduce resistance to severe impact compared with softer surfaces; proper sleeve fit and alignment help mitigate localized stress.

If compared to alternatives without nitriding, the nitrided SKD61 variant typically offers better sliding-wear performance, which is especially valuable in guided knockout applications where the sleeve-to-shaft interface experiences continuous motion.

Select the stepped ejector sleeve by matching the shaft (D), hole diameter (V), and overall geometry to your ejector and guide pin/coupler layout. The shaft diameter range is 4–20 mm, so choose a model where D fits the ejector shaft’s nominal size and intended clearance.

Use the tip diameter (P) to confirm step engagement with the ejector or mating features. Available P ranges include 3–3.5 mm, 3.5–4 mm, 4–5 mm, and 4–6.5 mm, allowing you to align step contact areas with your knockout system.

• Length (L): choose from 100–250, 125–300, 175–300, or 100–150 mm based on stroke and mold space.
• Dimension N: available bands include 50–120, 60–120, 80–150, 50–80, and 60–100 mm for the stepped layout.
• Tolerance/fit: the description notes H7 inner diameter tolerance; ensure your mating shaft fit targets the intended clearance for guided, low-friction movement.

Head thickness options are 8 mm (JIS) or 4 mm (T4); select the version that matches your die assembly depth and stacking requirements.