JIS Standard SKD61 Steel Straight Ejector Sleeves

Q: How do I choose the correct shaft diameter (D/P) and tolerance for this straight ejector sleeve?

This sleeve is available for D/P (shaft diameter) from 4 to 20 mm , with shaft diameter tolerances listed as -0.01/-0.02 or -0.01/-0.03 . Select the D/P value that matches your ejector shaft diameter, then account for the listed tolerance range when predicting fit and expected guidance clearance.

Q: What is the purpose of the JIS head and how do the 6 mm vs 8 mm head thickness options affect assembly?

The sleeve uses an ESJL construction with a JIS head to support repeatable fit to the mold support structure. Head thickness is available as 6 mm (JIS) or 8 mm (JIS) , so you should match this to the corresponding counter-dimension in your mold assembly to prevent mislocation from tolerance stack-up.

Q: How does nitriding influence wear resistance compared with leaving SKD61 untreated?

With this product, the nitrided surface improves wear resistance at the guidance interface during ejector travel. Compared with untreated SKD61, nitriding typically increases surface hardness and reduces scuffing/galling risk under cyclic motion, helping maintain bore accuracy and smooth straight movement over long production runs.

Straight ejector sleeves (SKD61 steel) feature a nitrided ESJL construction with a JIS head design, supporting stable guidance and consistent alignment during ejection. The H7 inner tolerance and controlled concentricity help improve assembly reliability.

ESJL single-sleeve design with JIS head for repeatable fit
Nitrided surface enhances wear resistance for long production runs
Controlled bore accuracy with H7 inner dia. tolerance supports tight guidance
Measured 0.06 mm concentricity supports smooth straight motion in molds

Request a Quote Back to Category

Specifications

20 configurations available

Head Thickness	Shaft Diameter Tolerance	D/P (Shaft Diameter) (mm)	V (Hole Diameter) (mm)	L (L dimension) (mm)	type
6mm(JIS)	-0.01/-0.02	4	1.5 ～ 2.5	80 ～ 200	-
6mm(JIS)	-0.01/-0.02	4.5	1.5	80 ～ 200	-
6mm(JIS)	-0.01/-0.02	5	3	80 ～ 300	-
6mm(JIS)	-0.01/-0.02	5	2 ～ 3	80 ～ 300	-
6mm(JIS)	-0.01/-0.02	5.5	3	80 ～ 300	-
6mm(JIS)	-0.01/-0.02	5.5	2 ～ 3	80 ～ 300	-
6mm(JIS)	-0.01/-0.02	6	2 ～ 4	80 ～ 450	-
6mm(JIS)	-0.01/-0.02	6.5	2 ～ 4	80 ～ 450	-
6mm(JIS)	-0.01/-0.02	7	2 ～ 4.5	80 ～ 450	-
6mm(JIS)	-0.01/-0.02	7.5	3	80 ～ 375	-
6mm(JIS)	-0.01/-0.02	7.5	3.5 ～ 4.5	80 ～ 375	-
8mm(JIS)	-0.01/-0.02	8	5	80 ～ 500	-
8mm(JIS)	-0.01/-0.02	8	2 ～ 5.5	80 ～ 500	-
8mm(JIS)	-0.01/-0.02	9	2 ～ 5.5	80 ～ 500	-
8mm(JIS)	-0.01/-0.02	9	3 ～ 6	80 ～ 500	-
8mm(JIS)	-0.01/-0.02	10	4 ～ 7	80 ～ 500	-
8mm(JIS)	-0.01/-0.02	12	4 ～ 7	80 ～ 500	-
8mm(JIS)	-0.01/-0.02	12	8 ～ 8.5	80 ～ 500	-
8mm(JIS)	-0.01/-0.03	15	9 ～ 10	180.01 ～ 500	-
8mm(JIS)	-0.01/-0.03	20	12 ～ 15	180.01 ～ 500	-

Product Guide

🏭Application Scenarios+

Where it’s used: This nitrided SKD61 straight ejector sleeve is used inside injection mold toolsets to support and guide straight ejection motion, helping reduce side-load and wear on ejector components.

Automotive connector and terminal molds: In high-cycle molds, stable sleeve guidance is critical for consistent ejection force transmission and repeatable positioning. The nitrided ESJL surface improves wear resistance, while the controlled H7 inner tolerance and 0.06 mm concentricity support smooth, aligned movement under repeated duty.

Medical device housings: These applications often require tight assembly reliability and predictable ejector alignment to maintain part quality. The JIS head geometry supports repeatable fit to the mold support structure, reducing tolerance stack-up during assembly.

Consumer electronics housings: For long runs where ejection uniformity impacts surface finish and dimensional stability, the accurate bore and straight guidance help minimize chatter and improve overall mold robustness.

Guidance stability: H7 bore accuracy for tight fit
Long-run durability: nitrided wear surface
Repeatable assembly: JIS head for consistent location

🔧Material & Process Details+

This straight ejector sleeve uses JIS Standard SKD61 steel and is supplied in a nitrided condition. SKD61 is commonly selected for hot-work and tooling applications where a balance of strength, toughness, and wear resistance is needed.

Heat treatment and surface engineering: The nitriding process hardens the surface layer, improving wear resistance against friction during ejector travel. The base metal remains tough enough to resist cracking under cyclic loading.

Wear resistance: enhanced by the nitrided surface for long production runs
Toughness vs. hardness trade-off: nitriding increases surface hardness while maintaining core toughness for impact and repeated ejection cycles
Machining implication: accurate bore finishing is important to achieve the specified H7 inner tolerance

Material comparison (brief): Compared with lower-alloy steels, SKD61 provides superior high-performance tooling behavior under cyclic wear; compared with higher-alloy stainless options, it generally offers better tooling cost-performance for standard production ejector guidance needs.

📐Sizing & Selection Guide+

To select the correct straight ejector sleeve, match the sleeve’s shaft diameter (D/P) to the ejector shaft diameter used in your design. This product supports D/P = 4 ~ 20 mm, and the provided shaft diameter tolerance values (e.g., -0.01/-0.02 or -0.01/-0.03) should be considered when calculating fit.

Bore fit and guidance: The inner diameter is specified with H7 tolerance. Ensure your ejector shaft selection results in the desired clearance for smooth motion while preventing excessive play. Because the product is nitrided and precision-ground for guidance, avoid oversizing shafts beyond your intended fit target.

Length selection (L): Choose the sleeve length L based on the required support engagement length in the mold. Available ranges include 80 ~ 200, 80 ~ 300, 80 ~ 450, 80 ~ 375, 80 ~ 500, and 180.01 ~ 500 (mm). Select the minimum length that maintains stable alignment through the full ejection stroke.

Head thickness: options are 6 mm (JIS) or 8 mm (JIS)—match to your mold housing/support counter-dimension
Hole diameter (V): supports V = 1.5 ~ 12 mm for alignment/retention features

Frequently Asked Questions

What does “H7 inner tolerance” mean for ejector sleeve guidance with SKD61 nitrided ESJL sleeves?+

The sleeve bore is specified to an H7 inner tolerance, which targets tight and consistent guidance. In practice, you should size the mating ejector shaft so that clearance/play meets your alignment and wear requirements. Using shafts that are too large can cause binding; too small increases lateral play and can affect ejection stability.

How do I choose the correct shaft diameter (D/P) and tolerance for this straight ejector sleeve?+

This sleeve is available for D/P (shaft diameter) from 4 to 20 mm, with shaft diameter tolerances listed as -0.01/-0.02 or -0.01/-0.03. Select the D/P value that matches your ejector shaft diameter, then account for the listed tolerance range when predicting fit and expected guidance clearance.

Which length (L) range should I use to ensure stable alignment through the full ejection stroke?+

Choose L based on required support engagement length in the mold structure. Available ranges include 80–200, 80–300, 80–375, 80–450, and 80–500, plus 180.01–500 (mm). Use the longest engagement that fits your mold layout to maintain alignment under load.

What is the purpose of the JIS head and how do the 6 mm vs 8 mm head thickness options affect assembly?+

The sleeve uses an ESJL construction with a JIS head to support repeatable fit to the mold support structure. Head thickness is available as 6 mm (JIS) or 8 mm (JIS), so you should match this to the corresponding counter-dimension in your mold assembly to prevent mislocation from tolerance stack-up.

How does nitriding influence wear resistance compared with leaving SKD61 untreated?+

With this product, the nitrided surface improves wear resistance at the guidance interface during ejector travel. Compared with untreated SKD61, nitriding typically increases surface hardness and reduces scuffing/galling risk under cyclic motion, helping maintain bore accuracy and smooth straight movement over long production runs.