SKH51 Steel Taperless One-Step Center Pins

These SKH51 steel taperless one-step center pins are used in injection mold tooling wherever repeatable workpiece or insert positioning is critical, especially during setup changes and high-run production maintenance.

• Automotive and electronics housings: Use the taperless geometry to locate mating locating sleeves or block features without relying on a tapered lead-in, supporting consistent alignment across repeated mold maintenance cycles.
• Medical device component molds: The one-step tip profile helps establish a stable datum for small-part alignment, reducing the likelihood of angular misalignment that can affect downstream cavity features.
• Die sets and machining fixtures: Pair the selected shaft diameter and compatible sleeve-hole tolerance with the pin for quick registration and reduced setup rework.

The SKH51 variant is suited to these applications because it provides strong wear resistance under frequent contact and handling, while the configurable head thickness, shaft diameter, and step/tip shapes help match common sleeve-hole layouts in mold base and fixture designs.

SKH51 is the specified tool steel for this center pin series. In typical tooling practice, SKH51 corresponds to the AISI M2 family (high-speed steel classification), offering a balance of wear resistance for repeated contact and controlled toughness for tooling use.

• Wear resistance: Expected to be high due to the high-alloy structure of SKH51, beneficial for frequent engagement with locating sleeves.
• Toughness trade-off: Like other M2-class steels, increasing hardness improves wear performance but can reduce impact toughness if severely stressed.
• Heat treatment state: Manufactured and supplied in a hardened condition appropriate for precision locating components; select pins with matching precision group (Standard/Precision) to control fit stability.

When choosing between precision groups, prioritize dimensional stability and locating repeatability for critical alignment features; for less demanding setups, Standard precision can be sufficient.

Select the center pin dimensions to match the mold base locating system: shaft diameter, step configuration, and compatible sleeve-hole tolerance are the primary fit drivers.

• Shaft diameter: Choose D/P in the range 1 ~ 12 mm. Respect shaft diameter tolerances of 0/-0.005 or -0.01/-0.02 to achieve the intended clearance/press behavior in your sleeve.
• Compatible sleeve-hole tolerance: Verify mating sleeve-hole tolerance against +0.005/0, +0.01/0, or H7 to maintain predictable alignment during repeated cycles.
• Tip and step geometry: Select Step shape B/C/D/E and Tip shape (No processing, B, C, G, R, T) to match the sleeve-hole counter/relief and the localization datum requirements.
• Length (L): Choose L from 70 ~ 200 up to 70 ~ 350 (series variants shown). This must satisfy mold setup depth while avoiding bottoming.

Head thickness is configurable in 4mm (T4), 6mm (JIS), and 8mm (JIS), which should match the locating block thickness and installation stack-up.