M2 Steel Two-Step Center Pins

These two-step center pins are used in precision injection mold tooling for repeatable mold alignment between the stationary and moving halves. The stepped profile creates a controlled seating action, helping locate the core/cavity stack consistently during every press cycle.

• Automotive connector and sensor housing molds: Stable tip positioning supports tight alignment so ejector and lifter components maintain correct clearance, reducing risk of flash and mis-mating.
• Electronics-grade plastic housings: The SKH51 wear-resistant construction helps preserve locating geometry under high-cycle operation where repeated contact loads can otherwise round or degrade pin tips.
• High-precision die/mold assemblies with guide sleeves: Compatibility with sleeve hole tolerances (e.g., +0.005/0, +0.01/0 or H7) supports consistent fits for reliable locating.

This variant is suited for applications requiring stable location over time due to the combination of two-step geometry and wear-focused SKH51 material.

This product uses SKH51 steel, a high-speed steel grade selected for its strong wear resistance at the localized contact areas found at center pin tips. In service, the two-step tip repeatedly engages locating features, so resistance to surface wear helps maintain alignment dimensions.

• Hardness & performance trade-off: SKH51 is typically supplied as a hard, wear-oriented steel; higher hardness improves tip wear resistance, while toughness is balanced for repeated mechanical contact rather than heavy shock loads.
• Manufacturing & heat treatment: The pins are ground and finished after heat treatment to achieve the stated tip tolerance needs (tight locating). Heat treatment is commonly hardened (and often tempered for dimensional stability), targeting a hard bearing surface for consistent seating.

Compared with softer alloy steels, SKH51’s wear-focused hardness better preserves locating geometry in high-cycle mold alignment. If ultimate impact toughness is the priority, a different steel family may be required, but for wear-limited positioning, SKH51 is an appropriate choice.

Select the center pin by matching its D/P (shaft diameter), step geometry, and overall length to the mold’s locating requirements. The shaft diameter range is 1 ~ 12 mm, with shaft diameter tolerance options of 0/-0.005 or -0.01/-0.02, which must be paired with the sleeve hole tolerance to achieve the intended fit.

• Choose the correct fit: For sleeve hole compatibility, the compatible sleeve hole diameter tolerance is +0.005/0, +0.01/0, or H7. Verify clearance at assembly using the selected shaft tolerance.
• Match the locating geometry: Select the step shape (A, B, C, D, E) and the second-step type (A, B, C, D, E). Tip-related ranges include A (0.5 ~ 2.5), fixed C (0.1 ~ 1.5), and E (0.1 ~ 2.5), plus chamfer features such as Q (0.1 ~ 0.3).
• Set overall length: Use L options based on your stack-up (e.g., 70 ~ 200 up to 70 ~ 350 and also 100 ~ 350 depending on configuration).

Ensure the tip chamfers and diameters align with the corresponding locating sleeve recess/profile so the stepped seating repeats without interference.