JIS Standard M2 Steel One-Step Center Pins Flat-Sided

One-step center pins with a flat-sided head are used to establish repeatable part-to-core alignment during injection mold assembly. The flat-sided design prevents rotation of the locating pin in the mating sleeve, which helps maintain stable locating and consistent cavity-to-core positioning across production cycles.

• Automotive connector and housing molds: In one-step tool designs, the stable anti-rotation head and one-step geometry improve alignment during build-up, supporting tight positional repeatability for thin-wall features.
• Electronics enclosure and snap-fit molds: Flat-sided locating reduces drift caused by handling and clamp-cycle vibration, helping maintain alignment of ribs, bosses, and gate/runner interfaces.
• Industrial consumer product molds: The hardened wear-resistant steel supports long service life for frequent changeovers where pins are repeatedly assembled and retracted.

The SKH51 variant is suited for these applications where accurate assembly, anti-rotation stability, and wear resistance directly influence dimensional consistency and mold downtime.

This center pin uses SKH51 steel (JIS M2 equivalent). In typical tooling practice, SKH51 is selected for its high wear resistance and ability to maintain dimensional stability under repeated contact with hardened mating components.

• Heat treatment: Hardened condition for wear resistance and service longevity (exact heat-treatment process details are not specified in the provided data).
• Hardness / performance: Hardened M2-class steels generally trade higher wear resistance against slightly lower toughness; this pin is intended for stable locating under assembly and repeated cycling.
• Manufacturing: Produced to precision shaft and tip tolerances with defined step geometry and tip processing options (e.g., specified tip shapes and chamfering).

If compared to lower-alloy steels used for basic alignment pins, SKH51 typically offers better wear resistance for long-running molds; compared to higher-cost alternatives, it balances performance for locating features that must resist fretting and micro-wear.

Select the pin D/P (shaft diameter) within 1 to 12 mm to match the mating sleeve bore size. Ensure the pin shaft tolerance is 0/−0.005, which means the pin is not oversized and can seat reliably without interference when used with the specified sleeve hole tolerance.

• Check sleeve fit: Use the sleeve hole tolerance +0.005/0 to achieve a controlled clearance/fit for smooth insertion and repeatability of locating.
• Choose overall length: Pick L from the available ranges (e.g., 70–200, 70–250, 70–300, or 70–350) based on mold thickness and the required engagement length in the sleeve.
• Step shape and tip geometry: Select the required step shape (A–E) and tip shape option that matches the locating/entering requirement. Tip tolerances can be ±0.01 or ±0.005 depending on the A/V setting.
• Head thickness: Choose T4 (4 mm) or the JIS head thickness options 4, 6, or 8 mm to suit the one-step tool stack-up.

For one-step molds, align the flat-sided head orientation during assembly so the anti-rotation feature engages correctly with the sleeve.