SKH51 Steel One-Step Center Pins

One-step center pins are used in injection mold tooling as a locating element between the mold base, die, and guide/sleeve system. The compact step geometry helps maintain repeatable positioning during die setup, reducing variability when the mold is removed and reinstalled.

• Automotive connector and small housing molds: ideal where thin alignment features and frequent service cycles demand stable sleeve location; the hardened SKH51 construction supports long-running alignment under contact wear.
• Electronics enclosures and precision brackets: the one-step interface promotes consistent die setting, helping maintain parting-line and cavity register stability during high cycle production.
• Press tooling and transfer fixtures: suitable for setups that require reliable orientation repeatability; tip/tolerance options (e.g., ±0.01, ±0.005, ±0.02) support fine fit with sleeve hole references.

Choose this variant when sleeve fit control and durable, hardened contact surfaces are critical to alignment accuracy.

SKH51 steel is a high-performance die/punching tool steel used for wear-resistant alignment components. In this hardened center pin application, it is selected to provide a good balance of wear resistance at the locating tip and sufficient toughness for repeated assembly/disassembly.

• Heat treatment: provided in a hardened construction state appropriate for high-contact locating use (pin-to-sleeve interface).
• Hardness and trade-offs: hardened SKH51 typically reaches high HRC levels to resist polishing/peening; higher hardness improves wear performance but can reduce toughness if over-tempered or if mounting stress is excessive.
• Manufacturing process: typically involves machining of the stepped geometry, tip contouring, then hardening and finishing to maintain tip tolerance for controlled locating.
• Material comparison: compared to lower-alloy, non-hardened steels, SKH51 offers superior wear durability for sleeve locating, but requires proper heat treatment control to avoid brittleness.

Selection starts with matching the shaft diameter (D/P) and the nominal diameter (No.) to your locating sleeve bore and guide system. This product supports D/P = 0.8 ~ 10 mm, with No. = 1 ~ 12, so choose the closest sleeve reference size to ensure proper engagement.

• Length/engagement: use the shaft length feature F = 50 ~ 70 mm for overall reach, and select the overall L according to mold thickness/spacing requirements (available ranges: 70 ~ 200, 70 ~ 250, 70 ~ 300, 70 ~ 350, and 70+).
• Fit and tolerance: the locating interface is intended for sleeve hole fits using +0.01/0 or H7 guidance; align the pin tip/tolerance to your sleeve clearance strategy (tip tolerance options include ±0.01, ±0.005, ±0.02).
• Tip geometry: choose the step shape (A, B, C, D, E) and tip shape (e.g., no processing, B, C, G, R, T) to match your sleeve lead-in and desired centering behavior.

Confirm that the stepped head thickness (T4 / 4mm(JIS) / 6mm(JIS) / 8mm(JIS)) fits your die setting stackup without interference.