Stepped Ejector Sleeves
Stepped shaft hollow sleeves for long ejector strokes. Guided shoulders ensure high column rigidity while limiting sliding contact wear.
Products
JIS Standard SKH51 Steel Precision Stepped Ejector Sleeve...
Precision Stepped Ejector Sleeves (ESVF) in SKH51 steel with thin-wall stepped design for stable guiding in molds. Re...
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JIS Standard SKD61 Steel Stepped Ejector Sleeves
Stepped Ejector Sleeves Primary Keyword (SKD61 steel) with nitrided surface for wear resistance and stable guidance i...
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JIS Standard SKD61 Steel Stepped Ejector Sleeves
Stepped Ejector Sleeves with built-in steps for guided knockout. (SKD61 steel) nitrided surface for wear resistance a...
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ESNF Type SKD61 Hardened Steel Stepped Ejector Sleeves
ESNF Type Stepped Ejector Sleeves (SKD61 hardened steel) with nitrided surface and H7 inner diameter tolerance for st...
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Japanese Standard SKD61 Steel Stepped Ejector Sleeves
Japanese Standard Stepped Ejector Sleeves with nitrided surface in SKD61 steel. Single-sleeve design supports H7 fit ...
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JIS Standard SKD61 Steel Stepped Ejector Sleeves
Stepped Ejector Sleeves (SKD61 steel) with nitrided surface finish and ESJF type for stable guidance. Built to JIS st...
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JIS Standard SKH51 Steel Precision Stepped Ejector Sleeves
Precision stepped ejector sleeves for injection molding, SKH51 steel. Thin-wall design supports small-diameter parts ...
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JIS Standard SKH51 Steel Precision Stepped Ejector Sleeves
Precision stepped ejector sleeves in <b>SKH51 steel</b> with ground boring for stable fit. Built to JIS standards for...
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JIS Standard M2 Steel Precision Stepped Ejector Sleeves
JIS Standard M2 Steel Precision Stepped Ejector Sleeves made with wire-cut & polished boring. Built for concentricity...
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JIS Standard SKD61 Equivalent Stepped Ejector Sleeves
JIS Standard Stepped Ejector Sleeves (SKD61 Equivalent) nitrided for controlled wear resistance. Single sleeve design...
View DetailsSelection Matrix: Stepped Sleeve Series
Compare the dimensions and design standards of our primary stepped ejector sleeve offerings:
| Series Type | Steel material | Guiding Section | Heat Treatment |
|---|---|---|---|
| ESVF (Precision) | SKH51 (HSS) | Precision ground guide length | Through-hardened 58-61 HRC |
| ESNF (Standard) | SKD61 (Hot-Work) | Standard guide length | Surface nitrided 900+ HV |
Selection tip: Match sleeve material to your resin type — use STAVAX for corrosive resins (PVC, POM) and SKD61 nitrided for glass-filled resins. For the complete material-resin pairing matrix, see our Ejector Sleeve Material Guide.
Troubleshooting: Stepped Sleeve Failure Modes
Refer to the table below to diagnose and resolve stepped sleeve failures in your molds:
| Common Problem | Root Cause | Engineering Solution |
|---|---|---|
| Fatigue cracking at shoulder step | Sharp corners build up localized stress concentration during long ejector stroke cycles. | Specify sleeves with optimized, stress-relieving shoulder transition R angles (R ≥ 0.5mm). |
| Sleeve guide seizure (Lock-up) | Inadequate guide bore clearance in mold plates or loss of lubrication. | Verify g6 tolerance on OD. Apply specialized PVD coating or switch to DLC lubrication-free. |
Engineering note: Most stepped sleeve failures originate at the shoulder radius. Increasing the fillet from R0.2 to R0.5 can triple fatigue life. For detailed analysis, see our shoulder breakage analysis.
Application Scenarios: Stepped Ejector Sleeves
Targeted scenarios where stepped sleeve architectures prove critical:
Medical Cleanrooms
Medical syringes require high-speed ejection. Dry-sliding conditions are mandatory to prevent lube contamination.
Why it fits: Through-hardened HSS ESVF sleeves are ground to extremely tight tolerances, allowing dry-running without seizing.
Optical Component Molding
Optical components cannot tolerate ejector pin misalignment, which causes visual lens parting line defects.
Why it fits: Stepped guide shoulders restrict radial runout to ≤0.010mm, guaranteeing flawless visual surfaces.
Frequently Asked Questions
What step ratios and shoulder dimensions are standard for ESVF and ESNF sleeves?+
How does a nitrided surface finish affect stepped sleeve operating temperatures?+
What tolerance class is applied to the outer diameter of stepped sleeves?+
About Stepped Ejector Sleeves
Stepped ejector sleeves (ESVF, ESNF series) provide a transition from a larger guide diameter to a smaller molding-end diameter. The step shoulder reduces plate contact friction and increases structural rigidity, but requires careful attention to the shoulder transition radius to avoid stress concentration failures. Available in SKD61 (nitrided) and SKH51 (through-hardened) options.
Engineering Resources
Need a Custom Quote?
Specify step diameters, shoulder R-angle, material, and surface treatment. DLC and TiAlN coatings available for cleanroom applications. Custom step ratios on request.