M2 Steel Round Shank Core Pins for Shaft Holes

Round shank core pins are used to form and maintain precise shaft holes in multi-cavity injection mold assemblies, where consistent alignment directly impacts assembly of inserts, mechanisms, and mating parts.

• Automotive connector housings: The quenched-hardened SKH51 construction and controlled shaft-hole interfaces help maintain dimensional stability over production cycles, supporting repeatable alignment for snap-fit or press-fit features.
• Consumer appliance latch/hinge components: The round shank geometry steadies the pin during ejection, reducing the risk of hole-position drift that can cause misalignment with shafts.
• Industrial device housings: Tight control of the shaft diameter and the L/F tolerance supports consistent core-to-cavity registration, improving repeatability for downstream assembly.

With the specified shaft-hole step/tip shapes (B/C/D/E for shaft holes and F/G for tip shape), this variant is suited for designs that require reliable locating and repeatable press-fit behavior.

This core pin uses SKH51 steel in a quenched hardened condition. SKH51 corresponds to AISI M2 (high-speed steel family), providing excellent wear resistance for hardened core applications where friction and repeated ejection loads are present.

• Heat treatment: quenched & hardened performance state to improve hardness and surface durability.
• Hardness / wear vs. toughness: the hardened condition increases resistance to wear and micro-abrasion at the bearing bore interface, while potentially reducing impact toughness compared with softer pre-hardened steels—so design relies on proper support and alignment.
• Manufacturing approach: typically produced via precision machining of the round shank and tip geometry, followed by hardening to achieve stable dimensions for tight press-fit hole formation.

Compared to general purpose tool steels, this SKH51 construction is better when long production runs demand higher wear resistance at the shaft-hole interface.

Select the pin variant by matching the shaft diameter (D/P) and overall length L to your core-to-cavity requirements for the shaft-hole feature.

• Shaft diameter: choose D/P = 2 ~ 10 mm to match the target hole/shaft interface. Confirm the pin-to-hole fit requirement using the specified shaft diameter tolerance 0/-0.005 (press-fit tendency).
• Nominal diameter: the corresponding nominial diameter = 2.5 ~ 10 mm should be consistent with your drawing’s core pin bore/guide specification.
• Length (L): choose L = 22 ~ 100 mm or up to 22 ~ 150 mm depending on tool stack-up. The L/F dimension tolerance +0.01/0 supports repeatable alignment during assembly.
• Tip and step shapes: use the specified Step shape B/C/D/E for shaft holes and the Tip shape F or G to match the bearing bore length and lead-in behavior.

Verify the bearing bore length F = 20 ~ 96/98/99/146/147/149 mm so the created shaft hole depth and engagement length meet the functional requirement.