JIS Standard SKD61 Steel Nitrided Straight Ejector Sleeves

Straight ejector sleeve components like this nitrided sleeve are used inside injection mold ejection assemblies to guide ejector motion and maintain concentric alignment under repeated cycling. The controlled H7 inner-diameter fit helps stabilize the sliding interface, reducing wobble and improving ejection repeatability.

• Automotive connector and bracket molds: Suitable for high-cycle ejection of plastic parts where consistent alignment reduces wear on mating ejector pins and sleeve bores.
• Consumer electronics housing molds: Works well for housings requiring smooth, low-deflection ejection because the nitrided SKD61 surface supports longer service life at the sleeve bore.
• Medical device housings with fine features: The precise bore tolerance supports stable assembly and consistent ejection behavior, which is critical for dimensional control around delicate molded geometries.

The nitrided SKD61 construction is specifically suited for environments where wear resistance at the sliding surface is more critical than bulk toughness.

This product is made from JIS Standard SKD61 steel, widely used for hot-work tooling and ejection components. SKD61 is comparable to AISI H13 in practical tooling selection, offering a good balance of wear resistance and toughness.

• Nitrided surface treatment: A nitrided layer improves surface wear resistance and helps the bore maintain a stable sliding interface.
• Heat treatment state: The performance intent is a nitrided finish on SKD61 to strengthen the surface while retaining a tough core (exact bulk hardness is not specified in the provided data).
• Hardness & trade-offs: Nitriding primarily boosts near-surface hardness and wear behavior; however, the core toughness remains important to avoid chipping under impact loading.

Compared with non-treated or lower-performance steels, nitrided SKD61 is typically preferred when the sleeve bore experiences frequent sliding and frequent start/stop cycles.

Correct dimension matching is essential for stable ejection guidance. This sleeve is specified by D/P (shaft diameter) = 3.5 ~ 20 mm with shaft diameter selection available in 0.01 mm increments, and by the bore size V (hole diameter) = 1.5 ~ 3 mm.

• Select D/P first: Choose the sleeve variant that matches the ejector shaft/pin diameter used in your mold design.
• Verify length L: Choose L = 40 ~ 200, 40 ~ 250, or 40 ~ 300 mm based on sleeve travel/stroke and the required support length.
• Check recess/geometry features: Confirm C = 2 ~ 3.5 mm and S (V hole diameter length) = 20 ~ 100 or 20 ~ 40 mm so internal clearances and functional reliefs align with your ejector assembly.

The inner bore is intended to meet H7 tolerance for stable fit; ensure mating ejector shafts/pins are specified accordingly to avoid excessive clearance or binding.