SKH51 Steel Pin-Point Gate Bushings Round Gate Transition

Pin-point gate bushings are used in injection molds to create a stable, repeatable connection between the sprue and the gate. This SKH51 quenched steel bushing variant is especially suited for precision gate placement where consistent melt onset prevents short shots and jetting.

• Automotive connector and sensor housings: Use the round gate transition to maintain accurate gate alignment through repeated opening cycles, supporting consistent filling for thin ribs and high-gate-count layouts.
• Consumer electronics casings: The controlled taper (A: 1–3°) and governed tip geometry help form a reliable gate without excessive flash, improving surface appearance near the part gate.
• Medical device housings: Wear-resistant SKH51 helps sustain dimensional stability in high-run molds, supporting repeatable gate size and transition during long production batches.

Choose the correct tip type (Normal/Acute) and shape family to match your required gate transition profile and part-flow sensitivity.

This bushing uses SKH51 quenched hardening steel, selected for its high wear resistance in gate-forming components. SKH51 is commonly aligned with AISI M2-equivalent high-speed steel performance levels, making it suitable for repeated thermal cycling and sliding contact during pin-point gate formation.

• Heat treatment: Quenched hardening construction, typically resulting in high hardness suitable for long mold runs.
• Hardness & performance: High hardness supports wear resistance at the gate tip; expect a trade-off where extreme hardness may reduce toughness compared with lower-alloy, water-hardened steels.
• Wear vs. toughness: For molds with frequent gate rework or abrasive additives, SKH51’s wear capability helps maintain tip dimensions; however, careful design for load concentration remains important.

Where other steels offer higher toughness, SKH51 is preferred when gate-tip wear control and dimensional stability across production are critical.

Select dimensions by matching the bushing to the gate bushing seat and the required gate transition profile in the mold core/cavity system.

• Outer diameter (D): Choose D = 6, 8, or 10 mm to match your bushing bore. Confirm fit based on the mold plate machining size and your intended retention method.
• Tip diameter (P): Maintain the specified P tolerance ±0.01 and select P from 0.5–0.6, 0.8–1.4, or 1.2–1.6 mm to set the gate neck diameter.
• Gate transition geometry: Use the fixed taper angle A = 1–3°, tip length C = 0.5–1.5 mm, and base length B = 5–20 mm. Tip tapered length G = 0.8–1.2 or 0.8–1.5 mm and overall L = 15–40 mm help control penetration and transition length.

For best assembly repeatability, align the bushing’s controlled P diameter with the gate-forming cavity features; the fixed tolerance makes it easier to keep gate dimensions consistent across builds.