Nitrided Ejector Sleeves

Where it’s used: Straight ejector sleeve components are installed around ejector pins in injection mold tooling to stabilize guidance during part ejection. The nitrided surface variant is suited for environments with repetitive stroke cycles and abrasive contact between the pin and sleeve.

• Automotive interior/exterior housings: In molds producing multi-cavity housings and stiff ribs, the sleeve maintains pin alignment to reduce scuffing and uneven ejection while supporting consistent clearance.
• Consumer electronics enclosures: For thin-wall components where ejection forces must be controlled, the bushing function helps achieve repeatable ejection, reducing risk of part deformation caused by misalignment.
• Packaging and appliance components: In high-throughput molds, nitriding improves wear performance for long service life under sustained cyclic loading.

How it’s used: Select the inner diameter to match the ejector pin size and choose the bearing length/overall length to position the guiding zone correctly in the mold plate stack.

This product is a nitrided ejector sleeve, selected for a hardened, wear-resistant surface that reduces friction and fretting at the ejector pin/sleeve interface. The nitriding treatment increases near-surface hardness, improving wear resistance under repetitive ejection cycles.

• Heat treatment state: Surface nitrided construction to enhance wear performance at the guiding area.
• Hardness and trade-off: Nitriding typically yields high surface hardness (often on the order of ~1,000 HV class), improving wear resistance while maintaining sufficient core toughness to limit brittleness compared with through-hardening approaches.
• Wear vs. toughness: Prioritize this variant where cycles and sliding wear dominate; for extremely impact-heavy applications, a designer may consider alternative through-hardened sleeve materials (not specified here) to emphasize core strength.

Exact steel grade and measured HRC are not provided in the input data.

Correct sizing is determined by matching the sleeve’s inner diameter and lengths to the ejector pin and mold stack. Use the provided ranges: I (inner diameter) is 1 ~ 9 in, D (outer diameter) is 1 ~ 11 in, L (overall length) is 3 ~ 14 in, H (head diameter) is 1 ~ 15 in, and bearing length is 1-3/4 in or 2-1/4 in.

• Pin clearance fit: Choose I to provide controlled running clearance around the ejector pin. If you have pin size and target clearance, compute the required I accordingly.
• Guiding zone positioning: Select bearing length (1-3/4 in or 2-1/4 in) to cover the portion of the pin that experiences the most guidance demand.
• Stack-up compatibility: Use L to fit the sleeve between adjacent plates and ensure proper support through the ejection stroke.
• Retention features: Use H for head/retention interface sizing in the mold assembly design; confirm it clears surrounding components.

Tolerances are not specified in the provided data, so confirm your internal clearance standards during final drawing approval.