JIS Standard Steel Ejector Punches Single-Stepped Shank

Spring-reinforced ejector punches with a single-stepped shank are used in injection mold tooling where stable ejection and controlled blow-down are required. In automotive connector and sensor housing molds, the stepped shank geometry helps maintain alignment in the ejector plate so the punch penetrates consistently through the die insert during high-cycle production.

They are also suitable for consumer appliance and electronics cover molds that use common round/rectangle/oblong punch tip profiles. The available hardened steel options improve resistance to tip wear from repeated punching actions, helping preserve dimensional accuracy over long runs.

For medical device and precision components, engineers can select hardened grades to balance wear resistance with toughness, reducing the risk of chipping at the tip. The design’s spring reinforcement supports smoother ejection stroke behavior, which is beneficial when part geometry creates uneven release forces.

• Use in ejector systems requiring repeatable penetration and stable feed
• Single-stepped shank supports reliable guidance through the ejector plate
• Hardened steel options improve long service life for precision punching

This series is offered in three hardened steel equivalents used for ejector punch work: SKH40 equivalent (powdered HSS), SKH51 equivalent (AISI M2 grade), and SKD11 equivalent (D2 grade).

SKH51 / M2 equivalent is commonly chosen for a strong wear–toughness balance in punch tips. SKH40 (powdered HSS) supports durability with improved micro-uniformity from powder processing, which can help stabilize performance under cyclic contact. SKD11 / D2 equivalent is a high-carbon chromium tool steel typically selected for excellent wear resistance, with a trade-off of reduced toughness compared with some HSS options.

• Hardened steel construction options are intended to improve wear resistance and extend service life
• Typical tooling practice is to supply punches in a hardened state suitable for precision punching; verify exact hardness upon quote
• Choose M2 (SKH51) for balanced wear/toughness, choose D2 (SKD11) for maximum wear resistance where chipping risk is controlled

To select the correct ejector punch, start with the shank diameter D and overall length needs of your mold’s ejector plate and guide clearance. This series supports D = 4–25 mm with a shank diameter tolerance of +0.005/0, m5, which is typically used to achieve a controlled sliding/fit in the mating hole.

Next, choose the tip type (round, rectangle, oblong, double flatted round, radius rectangle) and the corresponding tip dimension P = 1–18 mm. The tip length (B) is available as L, S, or X, so confirm the required penetration depth and contact area for your part ejection geometry.

For length coordination, match L = 40–80 mm and the full length alteration ranges LC = 32.5–70.1 mm and LCT/LMT = 33–70.1 mm to your ejector plate thickness stack-up. Consider spring-reinforced stroke behavior when selecting length to avoid over-compression.

• Match cavity/core hole diameter to D and target fit using the m5 tolerance
• Match punch tip profile and P to the part feature being ejected
• Select B (L/S/X) and L to control penetration depth and clearance