Japanese Standard SKD61 Steel Stepped Ejector Sleeves

Stepped ejector sleeves are used in injection mold tooling wherever precise ejector alignment is critical to prevent rubbing, mis-travel, or uneven ejection. This SKD61-based, nitrided variant is designed to maintain dimensional stability at the sliding interface while supporting a controlled stepped geometry that helps guide the ejector motion.

• Automotive connector and housing molds: In multi-cavity builds with frequent cycle duty, the stepped sleeve geometry improves concentricity and alignment, helping the ejector system return consistently after ejection.
• Consumer product tooling with high repeatability requirements: The H7 inner-diameter fit supports stable assembly positioning and reduces clearance-related wear during frequent ejector strokes.
• Precision die and mold assemblies (single-sleeve configuration): The single-sleeve design supports straightforward installation and consistent guidance in compact ejector layouts.

Choose this variant when you need wear-resistant sliding performance plus stable fit (H7) to protect ejector components under repeated movement.

Steel grade: SKD61 is a Japanese standard hot-work tool steel widely used for mold components requiring good heat resistance and toughness. It is commonly compared to AISI H13 in terms of application class (hot-work tooling performance).

Surface treatment: A nitrided surface is specified for improved wear resistance at the sliding interface. Nitriding increases surface hardness and abrasion resistance while keeping the core more tolerant to impact and bending stresses.

• Hardness: Exact HRC is not provided in the supplied data; hardness performance should be validated to your assembly’s contact pressure and duty cycle.
• Wear vs. toughness trade-off: The nitrided layer improves wear resistance, while the SKD61 core provides toughness for reliable ejector operation.
• Manufacturing relevance: Typical workflow includes machining of the stepped bore/shaft features, followed by nitriding to strengthen the contact surface.

If you need higher impact toughness than a nitrided surface provides, consider a non-nitrided SKD61 variant; if you need maximum sliding wear performance, nitriding is the key differentiator.

Select the stepped ejector sleeve by matching both the shaft diameter (D) and the tip/hole related dimensions to your ejector and guidance requirements, then verify the fit class for the inner bore.

• Shaft diameter, D: Available in 4 ~ 20 mm. Match D to the ejector/shaft diameter that interfaces with the sleeve.
• Tip diameter, P: Choose the correct step feature from 3 ~ 3.5, 3.5 ~ 4, 4 ~ 5, or 4 ~ 6.5 mm based on your ejector tip geometry.
• Hole diameter, V: Available 1.5 ~ 11 mm. Confirm this aligns with the locating or functional bore requirement in your assembly.
• Length options (L) and N dimension: L is offered across multiple ranges such as 125 ~ 250, 150 ~ 300, 200 ~ 300, 125, 150 ~ 250, and 100 ~ 250; N is offered as 50 ~ 120, 60 ~ 120, 80 ~ 150, 50 ~ 80, or 60 ~ 100.

This variant supports a H7 fit inner-diameter tolerance, so select the bore size to achieve the intended sliding clearance with your mating ejector parts. Use your mold assembly drawing to confirm overall reach using L and the step/interface location using N, since these dimensions govern guidance engagement.