JIS Standard M2 Steel Straight Center Pins with Tip Processed

Where it’s used: Tipped straight center pins are installed in ejector mechanisms to control locating accuracy between the core-side ejector set and the mating ejector sleeve.

Scenario 1 — Automotive connector and sensor housings: In high-cycle injection molding, consistent ejection alignment helps prevent scuffing and uneven wear on ejector components. The processed tip promotes stable centering at initial engagement, and the controlled sleeve fit (H7 inner diameter tolerance) supports repeatable assembly.

Scenario 2 — Medical device housings and caps: Tight alignment reduces positional variation during ejection, which is critical when tolerances for cosmetic surfaces and snap-fit features are tight. Tip processing improves centering reliability, helping maintain stable ejector operation.

Scenario 3 — Precision electronics enclosures: For small-diameter ejector trains (e.g., D/P range 0.8–10 mm), the JIS specification manufacturing supports consistent fit across production builds. The SKH51 (M2 steel construction) abrasion-resistant construction is well-suited for alignment-critical, wear-exposed ejector interfaces.

• Tip-processed geometry improves centering stability on first contact
• JIS standard production supports consistent mold-to-mold repeatability
• H7 sleeve compatibility supports a controlled, predictable locating fit

This series uses an SKH51 construction, which is commonly used as an AISI M2-equivalent high-speed steel for wear resistance in cutting and tooling applications. For these straight center pins, the steel is quenched and hardened to achieve high surface hardness for long service life at the ejector alignment interface.

• Hardness (HRC): The intended hardened condition targets abrasion resistance; exact HRC is not specified in the provided data, so hardness should be verified against the incoming material certificate for your lot.
• Wear resistance vs. toughness trade-off: Hardened M2-class steels improve resistance to fretting and sliding wear, while toughness is typically lower than annealed grades—important for pins that see repeated impact during ejection.
• Heat treatment state: Quenched & hardened construction (no nitriding or tempering values provided).

If you need higher impact tolerance, you’d typically consider alternative base steels or modified heat treatments; however, the H7-compatible, wear-exposed centering function here is designed around the SKH51 hardened abrasion-resistant approach.

Select by shaft diameter and fit first: Match the pin’s D/P (shaft diameter) range 0.8–10 mm to the corresponding ejector sleeve inner diameter. This series is designed for a compatible ejector sleeve inner diameter tolerance of +0.01/0 (H7), supporting a controlled locating fit.

Choose the correct nominal diameter: Use No. (nominal diameter) 1–12 mm and confirm it aligns with your sleeve bore selection for the required clearance and repeatability.

• Check diameter tolerance: Shaft diameter tolerance options are 0/−0.005 and −0.01/−0.02, which affects clearance under H7 sleeve conditions.
• Set length: Select the L dimension 50–200, 50–250, 50–300, or 50–350 mm based on required reach within the mold stack and ejector stroke.
• Confirm tip geometry: Pick Tip shape (B, C, G, R, T) and verify chamfer/taper features such as K (taper angle) 45–89° or 1–45°, plus R (tip chamfer radius) 0.2 mm and S 0.1 mm.

Tip-to-sleeve engagement: The processed tip is intended to center on entry; ensure the chosen tip shape/angle complements the sleeve bore length and the initial engagement zone to reduce misalignment.