JIS Standard SKH51 Steel Straight Ejector Sleeve Tapered

This tapered straight ejector sleeve made from JIS SKH51 is used to guide ejector components in injection molding and related tooling where alignment must remain stable under repeated stroke cycles.

• Die casting tooling: The tapered outer geometry and 4 mm head thickness help maintain consistent sleeve-to-shaft engagement, reducing misalignment risk during high-load ejection.
• Automotive and electronics connector molds: When tight fit is required around ejector shafts, the provided inner diameter tolerance reference +0.005/0 supports predictable guidance and repeatable ejection behavior.
• High-cycle production inserts: The hardened wear-resistant steel construction is suited for long service life in molds that experience frequent ejector actuation.

Its straight, single-sleeve component design simplifies integration into standard die sets while the concentricity options (◎0.003 or ◎0.005) support smooth travel through the mold.

SKH51 (JIS standard) is a high-speed steel grade selected for sliding and wear-guiding applications in mold ejector systems. It is typically supplied and used in a hardened condition (quench-and-temper practice) to balance wear resistance with sufficient toughness against shock loads during ejection.

• Wear resistance: SKH51 is known for good abrasion resistance at the sleeve-to-shaft interface, supporting stable guidance over long production runs.
• Toughness trade-off: Higher hardness improves scuff and wear resistance, but can reduce resistance to sudden impact compared with lower-alloy tool steels—making correct fit and alignment important.
• Heat treatment/process: Standard practice for SKH-series steels is quench and temper to reach the working hardness suited to ejector wear surfaces.

If lower-cost alternatives are considered, other tool steels may offer different toughness-to-wear balances; however, this product variant is specifically specified for the SKH51 hardened wear performance needed for tight-guidance die casting and ejection applications.

To select the correct sleeve geometry, start with your ejector shaft size and then match the sleeve hole/taper features to the mold’s core/cavity layout.

• Match shaft diameter (D/P): Choose from the available ranges: 2.5–3, 3.01–4, 4.01–5, 5.01–6, 6.01–7, or 7.01–8 mm.
• Select hole diameter (V): Use the corresponding hole diameter options available for each selection set, such as 1–2.4, 1–3.4, up to 1–7.4 mm, ensuring the hole aligns with the required guidance clearance and fit.
• Verify length (L): The fixed L = 20–110 mm must cover the effective guidance zone in your ejector path without bottoming on mating components.
• Concentricity considerations: Use the provided concentricity options (◎0.003 or ◎0.005) to control sleeve-to-shaft alignment performance.

The design intent is a tight fit; follow the specified inner diameter tolerance reference +0.005/0 when confirming assembly fit against the ejector shaft.