Precision Straight Ejector Sleeves
Straight tubular sleeves designed to eject circular ribs and bosses. Available in multiple heat treatments and premium tool steels for maximum sliding fatigue life.
Products
SKD61 Steel Short Straight Ejector Sleeves with Nitride C...
Short Straight Ejector Sleeves for die applications made from <b>SKD61 steel</b> with <b>nitrided</b> surface treatme...
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SKD61 Steel Nitrided Straight Ejector Sleeves (ESNV) Head...
SKD61 steel nitrided straight ejector sleeves (ESNV) with H7 inner bore tolerance and Head T=4 mm. Engineered for sta...
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SKD61 Steel Nitrided Straight Ejector Sleeves
SKD61 steel nitrided straight ejector sleeves with ESNV-LC design. H7 inner bore tolerance helps precise alignment. R...
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SKD61 Steel Nitrided Straight Ejector Sleeves Head T4
SKD61 Steel Nitrided Straight Ejector Sleeves with H7 inner diameter tolerance. Stable head T4 design for guided ejec...
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JIS Standard SKD61 Steel Nitrided Straight Ejector Sleeve...
JIS Standard SKD61 steel nitrided straight ejector sleeves with H7 inner-bore tolerance for stable press fits and wea...
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SKD61 Steel Nitrided Straight Ejector Sleeves
SKD61 steel nitrided straight ejector sleeves with Type ESN construction and <b>head T=4 mm</b> design. Inner bore to...
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JIS Standard SKD61 Steel Nitrided Straight Ejector Sleeves
SKD61 steel nitrided straight ejector sleeves for mold ejection assemblies. Tight H7 bore tolerance supports stable f...
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JIS Standard SKD61 Steel Straight Ejector Sleeves
Straight Ejector Sleeves (SKD61 steel) with nitrided bore and 4 mm head thickness for stable ejection in die sets. Re...
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JIS Standard SKD61 Steel Nitrided Straight Ejector Sleeves
JIS Standard SKD61 steel nitrided straight ejector sleeves with concentricity 0.06 for stable guidance. Single-sleeve...
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JIS Standard SKD61 Steel Straight Ejector Sleeves
Straight ejector sleeves for mold support. (SKD61 steel) nitrided ESJL type with JIS head, tight concentricity and H7...
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JIS Standard SKD61 Steel Straight Ejector Sleeves
JIS Standard SKD61 Steel Straight Ejector Sleeves with nitrided surface treatment for improved wear resistance. Confi...
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JIS Standard SKH51 Steel Precision Stepped Ejector Sleeves
SKH51 steel precision stepped ejector sleeves (ESVFX) for guided ejection. Tapered single-sleeve design with tight in...
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JIS Standard SKH51 Steel Straight Ejector Sleeve Tapered
SKH51 steel Straight Ejector Sleeve with tapered design and 4 mm head thickness for stable alignment. Built to tight ...
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JIS Precision Straight Ejector Sleeves (SKH51 Steel)
JIS Precision Straight Ejector Sleeves (SKH51 steel) ground boring for reliable bore quality. Single sleeve design fo...
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JIS Standard M2 Steel Precision Straight Ejector Sleeves
JIS Standard M2 Steel precision straight ejector sleeves with wire cutting & polishing bore finishing. Single sleeve,...
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SKH51 Steel Short Tapered Ejector Sleeves (T4 Head)
SKH51 Steel Short Tapered Ejector Sleeves with T4 head thickness provide stable ejection alignment. Configurable OD/I...
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JIS Standard SKD61 Steel Straight Ejector Sleeves Nitride...
SKD61 steel straight ejector sleeves with nitrided surface treatment for wear resistance. Concentricity suited for st...
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Nitrided Ejector Sleeves
Nitrided Ejector Sleeves provide stable pin support for part ejection and accurate alignment. Etched identification s...
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Oversized Ejector Sleeves
Oversized Ejector Sleeves used to eject parts and support ejector pins with a bushing function. Etched for quick iden...
View DetailsSelection Matrix: Straight Sleeve Materials
Compare our three standard straight sleeve tool steel offerings to find the right match for your polymer and cycle-life demands:
| Material Grade | Surface Hardness | Working Temp | Best For |
|---|---|---|---|
| Nitrided SKD61 | 900-1000 HV (Surface) / 48-52 HRC (Core) | Up to 550°C | High-temp molds, hot-runner setups, corrosive plastics. |
| SKH51 (HSS) | 58-61 HRC (Through-Hardened) | Up to 300°C | High toughness, fine blanking, standard medical molding. |
| M2 (Premium HSS) | 61-64 HRC (Through-Hardened) | Up to 320°C | Highly abrasive materials (glass-fiber, carbon-fiber filled resins). |
Decision rule: Match sleeve material to your operating temperature and resin type. SKD61 nitrided offers the best cost-per-shot for most applications. For full material property comparison, see our Ejector Sleeve Material Guide.
Fitting Clearance and Tolerances
Understanding inner diameter (ID) and outer diameter (OD) clearances is essential to prevent sliding wear:
Concentricity and Guide Fit
The outer diameter (D) is ground to g6 (-0.005/-0.020mm) to allow a smooth guided fit within the mold plate. The inner bore (d) is finished to H7 (+0.015/0mm) to match the center pin OD, establishing a precision slip clearance.
Preventing Thermal Seizing
Under high temperatures, tool steels expand. SKD61 has a linear expansion coefficient of 11.7 x 10^-6/°C. We ensure a minimum clearance of 0.010mm to guarantee the sleeve travels freely even at 200°C mold temperatures.
Engineering note: Target clearance at the tight end of the acceptable range — natural wear increases clearance over time. For the complete calculation method with worked examples, see our Clearance Calculation Guide.
Application Scenarios: Where These Sleeves Excel
See how different materials and finishes solve specific molding engineering challenges:
Abrasive GF Polymers
Glass-fiber filled resins (like PA66+30%GF) cause severe abrasion along the parting line, leading to flash.
Why it fits: Through-hardened M2 steel sleeves at 63 HRC withstand abrasive sliding wear much longer than standard hot-work steels.
Medical Cleanrooms
Standard liquid lubricants cannot be used in cleanroom molding due to contaminate risks, leading to dry-run friction.
Why it fits: SKH51 sleeves can be custom DLC-coated, enabling lubricant-free, high-speed ejection cycles without core seizing.
About Straight Ejector Sleeves
Our straight ejector sleeves feature high-precision concentricity (≤0.015mm) and a surface finish of Ra 0.1µm inside the bore to minimize sliding friction and maximize tool cycle-life.
Frequently Asked Questions
Why should I choose nitrided SKD61 straight sleeves over standard SKH51 sleeves?+
What inner diameter tolerance classes are available for straight sleeves?+
How does high glass-fiber content plastic affect straight sleeve wear and coating choices?+
Engineering Resources
Need a Custom Quote?
Specify your required OD/ID dimensions, material (SKD61/SKH51/M2), surface treatment (nitrided/standard), and length. Custom tolerance upgrades to H6 bore available.