SKH51 Steel One-Step Core Pins Flat-Sided

These flat-sided one-step core pins are used to locate and position mold cores with repeatable seating during injection molding tool build-ups. The flat-sided anti-rotation head helps prevent pin indexing or twisting during assembly, improving stability where ejector motion and core alignment must remain consistent over repeated cycles.

• Automotive connector and sensor housings: In multi-cavity molds, the one-step geometry supports consistent core engagement, while the anti-rotation head reduces misalignment that can affect part fit and gating consistency.
• Precision electronics enclosures: For thin-wall or tight-tolerance components, the pin’s tight shaft tolerance range (0/-0.003) supports accurate core positioning for reliable cavity definition.
• Medical device housing inserts: When repeatability is critical for post-processing and assembly, the stable one-step seating and anti-rotation feature help maintain core location through ongoing production.

The SKH51 steel variant is suited to these applications due to its hardened, wear-resistant construction, supporting long service life in tooling environments.

SKH51 is a high-speed steel grade commonly used in tooling where both wear resistance and dimensional stability are required. In terms of equivalency, SKH51 is typically treated as an AISI M2–equivalent high-speed steel, offering good hot hardness and tool-life performance compared with lower-alloy steels.

For core pin use, the material is expected in a hardened condition to achieve the wear-versus-toughness balance needed for repeated core seating. Typical heat treatment is quench and temper after hardening; the resulting hardness level is commonly in the high-HRC range for HSS tooling, supporting abrasion resistance at the pin tip and bearing areas.

• Wear resistance: High hardness supports resistance to fretting and localized wear from core engagement.
• Toughness trade-off: As hardness increases, impact toughness decreases; therefore, correct fit and surface finish matter to avoid chipping at corners.
• Compared to pre-hardened H13: H13 is often selected for general hot-work applications, while SKH51 is favored here for enhanced wear resistance at the contact surfaces.

Select the one-step core pin by matching the cavity/core engagement and the anti-rotation head seating requirements of your mold design. Use the provided shaft diameter range D/P = 0.8–10 mm and the tip diameter range A/AAC = 0.4–2 mm to ensure the pin diameter fits the mating bore and core guide interface.

• Shaft length: Confirm L = 6.5–100 mm and the bearing bore length F = 12–99.6 mm to achieve full guided support without bottoming.
• Step geometry: Choose the correct First Step Shape (B, C, D, E) and matching tip shape (B, C, G, R, S, T) to align the one-step seating surface with the core stop features.
• Tolerance/fit: The shaft tolerance is specified as 0/-0.003, so size callouts may be slightly below nominal. Ensure your core-side bore tolerances accommodate this negative tolerance to maintain seating without excessive clearance.
• Configurable dimensions: Parameters such as C (step taper width, 0.1–4 mm across options), CVC (0.01 mm increments within the listed ranges), and S (0.1–35 mm depending on configuration) are selectable—use your CAD drawing targets.

When in doubt, verify the mating bore dimensions in your core support plate and core to maintain consistent core seating and anti-rotation stability.