SKD61 Steel Nitrided Straight Ejector Sleeves

These SKD61 nitrided straight ejector sleeves are used in injection mold and die-casting tooling where the ejector system must maintain alignment under repeated cycling. The Type ESN straight construction helps provide stable guidance for straight-through ejector motion, reducing risk of binding during ejection.

• Automotive and appliance injection mold tooling: Suitable for ejector trains that need smooth shaft support under moderate-to-high wear conditions. The nitrided SKD61 surface improves scuff resistance at the sleeve/shaft interface while the head T=4 mm design supports consistent seating during assembly.
• Progressive die and multi-station molds: When frequent actuation and long service intervals are required, the precision inner bore tolerance H7 supports stable fit with matching ejector shafts, helping maintain uniform ejection timing.
• Die-casting related ejector systems: The wear-focused nitrided surface treatment is well matched to environments with abrasive contact and frequent reciprocation.

The core material is SKD61 steel, a hot-work tool steel commonly referenced as H13 equivalent in international practice. This sleeve is supplied with a nitrided surface treatment, which creates a hard wear-resistant compound/diffusion layer on the bore while keeping the core tough enough to survive impact and cyclic loading.

• Nitriding benefit: Improved scuff and abrasion resistance at the sleeve-to-ejector shaft interface, supporting longer guidance life.
• Hardness and trade-off: Nitriding typically targets a high surface hardness for wear resistance while preserving the steel’s toughness in the interior; excessive hardness at the core is generally avoided to reduce chipping risk.
• Heat treatment state: Delivered in a nitrided configuration suitable for guidance wear applications (no additional hardening specified in the provided data).

Compared with untreated or softer guidance bushes, nitrided SKD61 provides a better balance of wear performance and cyclic stability for ejector guidance.

Select the sleeve based on the ejector shaft diameter and the required mounting/guide geometry. The product provides D/P (shaft diameter) = 4 ~ 16 mm, and the corresponding V (hole diameter) = 1.5 ~ 10 mm range must align with the specific bore/feature you are designing around.

• Match shaft fit: Use the sleeve inner bore made to H7 tolerance to achieve stable guidance with the mating ejector shaft. Choose the sleeve variant whose D/P (4–16 mm) matches the actual shaft diameter used in your mold.
• Set guidance length: The L dimension is offered across 75–200 mm, 75–250 mm, and 100–300 mm depending on the specific size variant. Use the longest support length that fits your mold stack and maintains alignment without interfering with other components.
• Tolerance and fit considerations: Because the bore is H7, verify the shaft diameter tolerance class to ensure the intended clearance/press-fit behavior for your ejection system.

Head thickness is fixed as T=4 mm, supporting controlled seating during assembly.