SKH51 Steel Pin-Point Gate Bushings Tapered Tip

These SKH51 steel pin-point gate bushings are used in injection mold tooling where a controlled, repeatable gate transition is critical—especially for angle gate layouts that connect a sprue system to small gate openings.

• Automotive connector and bracket molds: The tapered tip geometry supports stable gate formation and helps maintain consistent melt flow during high-cycle production, reducing variability at the gate area.
• Electronics housings with fine pin-point gates: The tight P dimension tolerance (±0.01) improves locating accuracy in the gate bushing seat, supporting reliable assembly fit and repeatable part ejection behavior.
• Medical device components: When clean gate contact and controlled mold release are required, the tapered tip assists in managing the gate transition shape to promote consistent filling and reduce gate-related defects.

The SKH51 hardened steel base improves wear resistance, making this variant suitable for continuous production conditions where the gate region is actively stressed.

This bushing is manufactured from SKH51 steel, selected for its hardened wear performance in tooling contact zones. SKH51 is commonly used as an HSS-type grade (often aligned with AISI M2 in practical equivalency discussions), balancing hardness with machining wear resistance for gate-related features.

• Heat treatment state: Typically supplied in a hardened condition suitable for precision injection mold components; final hardness depends on the supplier’s heat-treatment cycle.
• Hardness & wear resistance: The hardened SKH51 condition targets high surface hardness for improved resistance to abrasion at the pin-point gate contact.
• Toughness trade-off: As with hardened tool steels, higher hardness generally reduces toughness margin; proper tool steel support and correct machining/handling reduce chipping risk.

Compared with softer steels, SKH51 provides stronger wear resistance for gate bushings; compared with more specialized carbide inserts, it offers better manufacturability and cost efficiency for precision metalworking.

To select the correct pin-point gate bushing, match the taper geometry and the seating dimensions to your core/cavity gate bushing location and the gate insert interface.

• Diameter match (D): Choose D = 2.5 ~ 10 mm to fit the outer diameter requirement of the gate bushing seat in the mold.
• Tip diameter control (P): The P (tip diameter) range = 0.3 ~ 1.2 mm and fixed P tolerance ±0.01 should be selected based on the targeted pin-point gate thickness/diameter for your part.
• Taper angles (A) and profile: Use A (taper angle) = 1 ~ 3° and select the appropriate Tip Type (Normal or Acute angle), with Cutting angle K = 20 ~ 60° and Tip length C = 0.2 ~ 0.5 / 0.3 ~ 0.8 / 0.5 ~ 1.5 mm to obtain the desired gate transition shape.
• Length selection (B, L): Pick B (excluding head/tip) from 4 ~ 6, 5 ~ 9, 5 ~ 30, 5 ~ 35, or 5 ~ 50 mm and confirm L = 8 ~ 25, 10 ~ 40, or 15 ~ 60 mm to ensure full engagement without over-penetration.

Because P is fixed at ±0.01, verify that your mating seat and gate land can tolerate this precision fit; keep the rest of the profile consistent with your cavity/core gate interface to avoid gate shape drift.