JIS Standard SKH51 Steel Pin-Point Gate Bushings (PGHTBL) with Head

Pin-point gate bushings are used in injection mold tooling to create controlled, repeatable transitions between the sprue/runner and the final round gate. This variant’s pilot tip hole supports precise alignment of the gate position, helping reduce part-to-part variation in fill and packing.

• Automotive connector and terminal molds: Use the round-transition geometry to stabilize gate-area support during injection; the head type helps maintain reliable seating under cycling.
• Consumer and appliance housings with small round gates: Select the matching tip diameter and SR range to tune the gate opening and ensure consistent gate formation during fast fills.
• General precision housings requiring alignment repeatability: The SKH51 wear-resistant steel supports long production runs where bushings experience frequent thermal cycling and contact loads.

Compared with non-piloted gate bushings, the PGHTBL structure improves positioning repeatability by locating the transition area with the pilot tip hole, which is critical for maintaining the target gate location over time.

This bushing is manufactured from JIS Standard SKH51 steel, a high-speed steel grade commonly used for wear-critical mold components. SKH51 is known for excellent wear resistance at the contact surfaces near the gate interface, where sliding and impact loads can occur during ejection and thermal cycling.

• Typical hardness: SKH51 is commonly supplied in the quenched & tempered range and is often used at high hardness levels (commonly around the 60–62 HRC class) to balance wear and toughness.
• Heat treatment (process): Hardening followed by tempering is used to achieve the working hardness; in service, localized wear and micro-chipping resistance are improved at the gate-contact tip.
• Trade-off: Higher hardness improves wear resistance, but can reduce toughness versus lower-hardness steels—so correct bushing sizing and proper alignment are important.

Compared with more general tool steels, SKH51’s high-speed steel characteristics provide a more robust solution for long-life gate bushings subjected to repeated contact at the pin-point transition.

To select the correct PGHTBL steel pin-point gate bushing, match the mold’s required round gate transition dimensions to the offered spec ranges. Start with D (outer diameter)—available in 3, 4, 5, 6, 8 mm—to ensure the bushing fits the corresponding sprue bushing pocket and maintains concentricity to the gate.

• Gate geometry tuning: Choose P (tip diameter) from 0.4–0.6, 0.4–0.8, 0.6–0.8, or 0.8 mm and select the SR range (1, 1–1.25, 1.25–1.5, 1.5–2 mm) to define the transition and pilot-tip shaping.
• Length setup: Match B (5–10.5 up to 5–32.5 or 6.5–31.5 mm, depending on the selected variant) and overall L (20–40 or 20–60 mm) to the mold plate thickness and runner/sprue layout.
• Alignment reference: Use G (1.2–3 or 1.5–4 mm) for the required distance from gate tip to SR feature.

For fit, the product description indicates an outer diameter tolerance reference of 0/-0.005 mm, so plan cavity/core machining and clearances accordingly to achieve a stable seating without interference.