SKH51 Steel Pin-Point Gate Bushings Angle Gate Transition

These SKH51 pin-point gate bushings are used in injection mold tooling to form precise, repeatable runner-to-cavity gate features. The angle gate transition and tapered tip help stabilize gate entry geometry and promote smoother runner flow, which reduces gate defects tied to inconsistent gate formation.

• Automotive and appliance connector molds: Ideal for pinpoint gating where small gate size and controlled flow are needed to limit cosmetic impact and maintain dimensional consistency across production cycles.
• Electronics housings with delicate appearance surfaces: The tapered tip and selectable tip types/shapes support consistent gate vestige formation, improving surface quality after ejection.
• Industrial fluid/thermoplastic components: The hardened SKH51 construction supports long service intervals in high-cycle molds where bushings experience wear from repeated pin-point gating and extraction.

The SKH51 variant is suited to these applications because it offers strong wear resistance while maintaining the sharp geometry necessary for controlled gate formation.

SKH51 is a high-speed steel commonly regarded as comparable to the AISI M2 family, selected for tooling surfaces that need high wear resistance. In pin-gate bushing service, the hardness supports resistance to abrasion at the tapered tip where flow and gate formation contact occur repeatedly.

• Heat treatment state: Typically supplied hardened (quenched and tempered) to reach stable operating hardness for production molds.
• Hardness & performance trade-offs: Higher hardness improves wear resistance and tip durability, but excessive hardness can reduce toughness; proper tempering balances crack resistance during mold shutdown/handling and thermal cycling.
• Wear vs. toughness: Compared with lower-alloy steels, SKH51 prioritizes wear resistance; compared with ultra-fine carbide wear grades, it generally offers a more favorable combination of hardness stability and toughness.

The hardened condition is critical for maintaining tip geometry (tip diameter/angle) over repeated extraction cycles.

Selection starts by matching the bushing exterior and gate tip dimensions to the mold’s sprue/runner gate system. Use D (outer diameter) = 2.5 ~ 10 mm to fit the available bushing pocket, and confirm that your mold insert bore can accommodate the intended fit.

• Tip diameter and gate opening control: Choose P (tip diameter) = 0.3 ~ 1.2 mm and the V (tip diameter) = 1.5 ~ 5 mm (if applicable to the selected shape) to achieve the required pinpoint gate size and flow restriction.
• Geometry tuning: Select A (taper angle) = 1 ~ 3°, C (tip length) = 0.2 ~ 0.5 / 0.3 ~ 0.8 / 0.5 ~ 1.5 mm, and R (tip radius) = 0.6 ~ 5 mm based on how aggressive you want the transition from runner to gate to be.
• Dimensional tolerance: The P dimension tolerance is ±0.01, supporting consistent assembly alignment of the tip diameter across production.

Finally, choose the mold-side features to maintain consistent clearance during assembly; use the fixed ±0.01 P tolerance when validating gate opening targets.