One-Step Core Pins Flat Sides

One-step core pins with flat sides are used in injection mold tooling where precise core location and repeatable ejection stroke are critical. The flat-sided anti-rotation head helps maintain angular stability during cycle start/stop, reducing wear at the bearing interface and helping ensure consistent core alignment.

In automotive and appliance connector molds, these pins support stepped core geometries that must eject housings or terminal components without drifting. The one-step profile with controlled L-dimension tolerance is suited to molds that require stable positioning under high production rate and frequent core loading.

For medical device housings and other tight-tolerance plastic parts, choosing a hardened steel option improves dimensional stability at elevated mold temperatures. Available shaft diameter and tight tolerance bands allow designers to match bearing length and step location to the core support system.

• Anti-rotation locating via flat sides for stable core engagement
• Repeatable ejection supported by L-dimension tolerance control
• Steel options for wear resistance in continuous production

This core pin series is selectable across multiple steel grades depending on wear, toughness, and expected mold temperature. Options include SKD61 (commonly used as an H13-class hot-work tool steel), SKH51 (high-speed steel for improved wear resistance), NAK80 (pre-hardened, commonly selected for dimensional stability), DH2F (tool steel variant for wear resistance applications), and STAVAX ESR (ESR-refined tool steel for cleaner microstructure).

Exact hardness (HRC) and heat treatment state are not provided in the supplied data, but these grades are typically chosen to balance wear resistance vs. toughness. Higher-wear grades such as high-speed steels generally trade slightly lower toughness for increased abrasion resistance under sliding contact. For corrosive or cleanliness-sensitive processes, stainless SUS440C can be considered versus carbon/tool steels.

• Wear resistance: SKH51 / NAK80 / DH2F selections
• Balance for hot molding: SKD61 class steels
• Cleaner microstructure: STAVAX ESR
• Material alternatives: MAS1C, PROVA400, SUS440C (select by application requirements)

Selection starts with the shaft diameter D/P (1 ~ 20 mm) and then the overall locating geometry defined by the L dimension (12 ~ 30 mm). To ensure stable anti-rotation seating, match the flat-sided head and stepped profile to the mold plate and core support bore system.

Use the tolerance bands to verify fit during assembly. The shaft diameter tolerance is available as -0.01/-0.02 or 0/-0.005, while the L-dimension tolerance is available as +0.02/0, 0/-0.1. Choose the tighter match for sliding/bearing setups where clearance and repeatability affect ejection alignment.

• Step geometry: select first step shape 1A–1E, plus step parameters such as A (0.4–4 mm) and C (0.1–4 mm or grouped ranges)
• Bearing length: confirm F (10 ~ 28 mm) to align with the core/mold interface length
• Tip features: choose tip shape (No processing, B/C/G/R/T) and gradient tolerance ±0.015/±0.01/±0.01

Finally, verify the tip alteration parameters (e.g., RE 0.5 ~ 2 mm) and the available tight tolerances on diameter and L for reliable locating without binding.