Two-Step Core Pins Head T=4 mm

Two-step core pins with a 4 mm head thickness are used in injection mold tooling where the core must be positioned and supported with high repeatability. The stepped geometry provides a controlled seating action, helping maintain stable core-to-bushing alignment during production.

In automotive connector and housing molds, these pins support precise core alignment for thin-wall features. The tightened shaft diameter specification (0/−0.005 mm) helps ensure consistent fit through the steel guide structure, supporting smooth, reliable ejection.

In electrical appliance and precision casing molds, the two-step bearing area supports load distribution while limiting lateral play. The controlled L dimension tolerance (+0.02/0 mm) helps lock stack-up consistency across multiple cavities or components.

• Use where stable ejection and alignment depend on tight shaft-to-bushing clearance.
• Choose the specified step shapes (first/second step options) to match your core-to-support layout.

This stepped core pin series is available in several common mold steels, selected for wear resistance and dimensional stability in guide and support roles. Options include SKH51 (AISI M2 equivalent), SKD61 (AISI H13 equivalent), NAK80 (corrosion-resistant, pre-hardened tool steel), DH2F, SUS440C, and MAS1C.

Hardness and performance depend on the selected grade and its heat treatment state. In general, high-hardness grades (e.g., tool steels such as SKH51 or SKD61 after proper heat treatment) offer improved wear resistance, while maintaining toughness through controlled tempering to avoid brittleness in ejection/guide cycling.

• Select quenched & tempered tool steels when higher abrasion resistance is required.
• Select corrosion-resistant grades (e.g., NAK80) when surface stability in humid or chemically active environments matters.
• For long-life guide surfaces, confirm heat-treatment and target hardness for the intended cycle rate.

Correct selection starts with matching the shaft diameter D/P (1–20 mm) to your core bore or bushing fit requirement. This series specifies shaft diameter tolerance of 0/−0.005 mm, so confirm whether your mating bushing bore expects a near-zero clearance or intentional interference-free guidance.

Next, set the overall functional length using the L dimension (12–150 mm, depending on configuration). The L tolerance is +0.02/0 mm, meaning length will not be shorter than nominal, which supports tight stack-ups in cavity/core assemblies.

• Choose the first step diameter type A (0.51–5 mm) and the first-step geometry (CA/CB/CC/CD/CE) to match the seating diameter on your core side.
• Select the second step shape (A/B/C/D/E) and tip diameter E (0.5–5 mm) to align with the guide/support profile.
• Verify bearing bore length F (10–30 mm) and chamfer widths (e.g., G 0.1–0.5 / 0.1–0.2) for smooth assembly and reduced stress concentration.

If you are varying step shapes, treat step dimensions as configurable while the head thickness is fixed at T = 4 mm for this variant.