JIS Standard SKD61 Steel Nitrided Straight Ejector Sleeves H7 Bore

Straight ejector sleeves are used inside injection mold bases to guide ejector pins and distribute movement smoothly during opening and ejection. This SKD61 nitrided, JIS-head variant is suited for production molds where stable alignment and resistance to abrasive wear are critical.

In automotive connector and housing molds, repeated short-cycle ejection can polish or scuff sliding surfaces. The nitrided SKD61 case improves surface wear behavior, while the H7 inner-bore tolerance helps maintain consistent press-fit alignment with guiding pins.

For consumer electronics and appliance parts (e.g., snap-fit covers and brackets), ejector systems must stay concentric to avoid sticking and uneven part release. The JIS head geometry supports compatibility with standard ejector sleeve retaining features, reducing assembly variability.

• Use when stable guiding under repeated cycles is required
• Choose the correct bore tolerance (H7) for predictable fit
• Ideal where wear from ejector pin sliding is a primary concern

This straight ejector sleeve is made from JIS Standard SKD61 steel (tool steel commonly mapped to AISI H13-type behavior in tooling applications). The sleeve is nitrided, forming a hard surface case that increases abrasion and galling resistance for sliding ejector interfaces.

Key benefits and trade-offs:

• Nitrided SKD61: improved wear resistance at the sliding surface with minimal dimensional change compared to deeper carburizing/through-hardening approaches.
• Core toughness remains sufficient for ejector guidance duty, but extreme plastic-deformation loads should still be avoided to prevent premature wear.
• Hardness (HRC): hardness is typically highest at the nitrided case; however, exact HRC values are not specified in the provided data, so verify with your supplier’s material/test certificate for confirmation.

If you need alternatives, un-nitrided tool steels may deliver lower surface wear performance, while higher-wear surface treatments can improve abrasion at the cost of tighter process control and qualification needs.

Select ejector sleeve dimensions by matching the shaft (pin) size and the housing recess geometry in your mold design. This model supports D/P (shaft diameter) = 3.5 ~ 10 mm (in 0.01 mm increments by designation), with an inner-bore tolerance of H7 for stable guiding.

• Confirm your ejector pin outer diameter and choose the sleeve D/P in the required 3.5–10 mm range.
• Match the sleeve V (hole diameter) of 1.5–4 mm to your pin/hole requirement.
• Set sleeve L (length) based on your mold stack-up: available as 40–200, 40–250, or 40–300 mm depending on the configuration.
• Verify recess diameter C = 2–4.5 mm and the S (V hole diameter length) options of 20–40 or 20–50 mm to fit the retaining/step features.

Because the inner bore is H7, ensure the pin diameter (and any press-fit interference allowance) is specified to achieve the intended alignment and repeatability. Length and head thickness are configurable by JIS standard options: 6 mm (JIS) or 8 mm (JIS).