Taperless One-Step Core Pins

This taperless, one-step core pin design is used in injection mold tooling where stable core-to-cavity alignment is critical and where a second seating step would add cycle variability. The one-step profile with no second step helps ensure consistent location and repeatable assembly, supporting tight fit between the guide/bearing area and the mold plate.

Automotive connector and sensor housings: For multi-cavity molds that repeat alignment thousands of times, the configured shaft diameter and fine fit tolerance (example given: 0/-0.005) supports reliable core positioning under thermal cycling.

Medical device and diagnostic housings: When corrosion resistance is required, selecting a corrosion-capable grade (e.g., SUS440C) and a precision one-step geometry supports stable mold operation and reduces misalignment risk during production runs.

Electronics enclosures: For fine-detail plastics requiring consistent part geometry, the one-step seating improves repeatability, while the available tip/step shapes help match specific cavity/core interfaces without adding an extra machining step.

These core pins are offered in SKH51, SKD61, NAK80, and SUS440C, allowing engineers to tailor wear resistance and corrosion performance to the molding application.

• SKH51 (high-speed steel, typically similar to AISI M2-class): very high hardness for abrasion/adhesive wear resistance; excellent for long-run precision guidance, with the usual trade-off of reduced toughness compared with softer tool steels.
• SKD61 (H13 equivalent class): balanced toughness and heat checking resistance for thermal cycling; commonly used when strength under repeated heating/cooling matters.
• NAK80: corrosion resistance and smooth wear behavior suitable for plastic molding environments where surface stability is prioritized.
• SUS440C: stainless option chosen for corrosion resistance demands.

Heat treatment is typically selected to reach functional hardness for guide/contact surfaces (commonly quench & temper for tool steels such as SKD61/SKH51 and appropriate hardened conditions for stainless grades), then polished/finished to maintain the required fit and bearing geometry.

Select the core pin dimensions by matching the shaft diameter D/P, the overall L length, and the tip geometry to your mold’s core bore and supporting guide features. This product supports a D/P range of 0.8 ~ 16 mm, and an L dimension range of 12 ~ 100/120/150 mm depending on the configured length set.

• Step/tip interface: Choose tip diameter A/AAC (0.4 ~ 5 mm) and select tip shape (B/C/G/R/S/T) plus first step shape (B/C/D/E) to match your cavity/core interface clearance and seating behavior.
• Fit control: Use the provided length tolerance examples such as 0/-0.05 (and the example shaft fit tolerance 0/-0.005) to ensure proper seating without over-insertion. Maintain the expected clearance on the mold bearing bore so the “one-step” seat reaches the designed stop.
• Bearing bore length: Verify F (10 ~ 28 mm) aligns with your bearing/support zone depth.

Configurable dimensions include material, D/P, L, A/AAC, and geometric features (tip/step shapes). Fixed elements include RE 0.5 ~ 2 mm and C 0.1 ~ 4 mm, which should be considered when planning the pocket/bearing machining.