JIS Standard SKD61 Equivalent Stepped Ejector Sleeves

These nitrided stepped ejector sleeves are used in injection mold tooling where consistent ejector alignment is critical. The stepped profile acts as a mechanical guide, helping stabilize ejector movement during high-cycle part ejection, especially in molds that see frequent start-stop production.

• Automotive and appliance housings: In ejector systems for medium-to-large plastic parts, the sleeve supports repeatable ejection guidance, reducing stick-slip behavior when dimensional loads cycle thousands of times.
• General electronics enclosure molds: Single-sleeve stepped geometry helps maintain coaxiality with the ejector pin set, supporting stable fit across the available shaft diameter range (D: 5–20 mm).
• ESJFC stepped ejector sleeve assemblies: The product is designed specifically for ESJFC stepped ejector sleeve applications, making it suitable when the mold designer requires a controlled wear surface for long service life.

The nitrided variant is well-suited for abrasive wear at the sleeve interface while preserving dimensional control needed for reliable ejection.

This component is specified as a JIS Standard SKD61 equivalent stepped ejector sleeve. SKD61 is widely treated as comparable to AISI H13-grade tooling steel in terms of hot-work die steel performance, offering good toughness for cyclic molding loads.

• Surface condition: The sleeve is nitrided, providing a hard, wear-resistant surface layer to improve resistance to repetitive sliding contact.
• Hardness and trade-off: The nitriding hardens the near-surface region for wear control, while the SKD61-equivalent steel body maintains toughness to resist chipping and cracking under cyclic ejection forces. Exact HRC values are not provided in the supplied specifications.
• Wear vs. toughness: Nitriding primarily improves wear performance; deeper toughness is controlled by the base steel condition inherent to SKD61-equivalent tooling materials.

Compared with un-nitrided variants, nitriding improves controlled wear at the sleeve-to-ejector interface, which is beneficial for stable fit over long runs.

Select the stepped ejector sleeve by matching the mold’s ejector guide requirements to the specified dimensional set. Start with D (shaft diameter) in the range 5–20 mm—this should correspond to the ejector shaft diameter it will guide.

• Tip and guiding geometry: Choose P (tip diameter) within 3.5–10 mm to match the mating stepped feature of the ejector/pin assembly.
• Hole sizing: Set V (hole diameter) to 2–2.5 mm, and use the fixed S (V hole diameter length) of 1–150 mm to match required through-hole engagement length.
• Length matching: Select L from the available ranges (e.g., 50–400, 50–600, 50–800, 50–900) consistent with your mold stack-up.
• Stepped section height (N): Choose Dimension N from the corresponding ranges (e.g., 17–400, 17–600, 17–800, 17–900) to achieve proper guidance overlap.

Account for assembly tolerances in the mold design: nitrided surfaces improve wear resistance, but dimensional fit still depends on the overall ejector and sleeve tolerance scheme used for the ESJFC stepped ejector sleeve assembly.