JIS Standard SKD61 Steel Straight Ejector Sleeves Nitrided ESJBC

These nitrided SKD61 straight ejector sleeves are used in injection mold die assemblies where ejector alignment must remain stable over repetitive cycles. The sleeve’s single-piece construction provides continuous bore support, helping minimize side loading on ejector components during ejection.

• Automotive connector and housing molds: suited for high-cycle ejection systems that see frequent abrasion, because the nitrided surface treatment improves wear resistance and reduces scuffing at sliding interfaces.
• Appliance and industrial part molds: helps maintain concentric positioning in die-set guides, supporting smoother stroke consistency when ejector travel length varies across platforms.
• Die assemblies for precise alignment: the JIS head configuration integrates into standard mold layouts, making it easier to fit into existing ejector sleeve and pin arrangements.

Choose this ESJBC variant when you need reliable fit and stable alignment combined with improved surface durability on the sliding surfaces.

The sleeves are made from JIS SKD61 steel, a widely used hot-work tool steel (often referenced as H13-type in industry comparisons) chosen for its balance of toughness and wear performance in molding wear environments.

• Nitrided surface treatment: improves near-surface hardness and wear resistance to resist abrasion during sliding motion.
• Hardened base steel (typical tool practice): SKD61 is hardened and tempered prior to finishing; nitriding is then applied to enhance surface durability while retaining tougher core behavior.
• Trade-off: nitriding increases surface wear life, while the tempered core helps prevent brittleness under repeated ejection loading.

Compared with non-nitrided SKD61, this variant is intended for longer service life where scuffing and rubbing at the sleeve interface are common.

To select the correct straight ejector sleeve, match the sleeve’s functional diameters to the ejector and guide requirements in your mold assembly. Use P (tip diameter) from 4 ~ 18.1 mm as the primary sliding/fit-determining dimension, ensuring it matches the mating ejector pin/guiding feature design.

• V (hole diameter): select from 2 ~ 2.5 mm for the relevant through-bore function; confirm it aligns with the mating pin or clearance design in your assembly.
• L length: choose from 50 ~ 400 mm, 50 ~ 800 mm, or 50 ~ 900 mm depending on required ejector stroke support.
• S (V hole diameter length): this fixed parameter is 1 ~ 150 mm; set it to cover the guided engagement length needed for stability.
• Head thickness: select 6 mm (JIS) or 8 mm (JIS) to fit your die layout and seat depth.

Confirm bore and fit strategy with your tolerancing assumptions; the nitrided surface may slightly change functional wear behavior over time, so base clearances should follow your design targets.