JIS Standard SKH51 Steel One-Step Center Pins

One-step center pins are used in injection mold tooling to establish repeatable center positioning between a mating jig, die set, or locating sleeve. Their one-step geometry helps the assembler achieve stable axial location during build-up, reducing the risk of drift over repeated cycles.

• Automotive connector and housing molds: Use the controlled shaft diameter (D/P 0.8–10 mm with 0/−0.005 mm control) to maintain consistent alignment of locating sleeves and improve part-to-part positional repeatability on high-run production.
• Medical device housings and fixture tooling: The JIS-standard manufacture and consistent tip/taper geometry support reliable centering during jig loading, helping maintain concentricity for precision components.
• General jigs and dies: Select the appropriate step shape (A–E) and tip processing option to match the receiving block/fixture features, allowing easy assembly with predictable fit.

This variant uses JIS Standard SKH51 steel, a hardened high-speed steel grade commonly selected for locating components that must resist wear. In service, the hardened condition supports high wear resistance at the pin/sleeve contact areas, improving dimensional stability across repeated assembly cycles.

• Wear vs. toughness balance: SKH51’s hardness provides durable sliding and contact wear performance, while some toughness trade-off can occur compared with tougher mold steels—this makes correct fit and alignment important to avoid edge loading.
• Heat treatment state: The product is manufactured as a hardened-steel center pin design intended for long-life wear resistance in jigs and dies.
• Typical comparison: If you need higher shock toughness, alternative die steels may be considered; however, for sleeve-hole centering durability, SKH51’s wear-focused hardened performance is the intent.

To select the correct one-step center pin, match both shaft diameter and the one-step geometry to the mating sleeve-hole and receiving fixture features. Start with D/P (shaft diameter) = 0.8–10 mm and confirm the shaft fit control to 0/−0.005 mm, which is critical for reliable sleeve-hole engagement.

• Choose nominal diameter: Use No. (nominal diameter) 1–12 as your catalog baseline, then verify the corresponding shaft diameter D/P.
• Select step and tip geometry: Pick the required step shape (A, B, C, D, E) and tip shape (No processing, B, C, G, R, T) based on the receiving part’s counter/center features.
• Check overall dimensions: Use Head thickness options (T4, 4 mm JIS, 6 mm JIS, 8 mm JIS) and L range (70–200/250/300/350 up to 70–300 depending on option) to ensure clearance and correct engagement length.
• Tolerance guidance: Tip tolerance is specified as ±0.01 or ±0.005, so choose the tighter tolerance when you require higher centering repeatability.