Ejector Punch Blanks - Metric with Center Dowel Hole

These metric ejector punch blanks are used inside progressive and transfer die tooling where punch-to-die alignment directly affects part quality. The center dowel hole provides die spotting and stable guidance, helping maintain repeatable positioning under cyclic press loads.

• Automotive and appliance progressive dies: When multiple stations must index precisely, the dowel-referenced blank improves punch alignment, reducing side-load and improving cycle-to-cycle consistency.
• Die spotting and ejector return assemblies: The blank format supports controlled punch movement and stable guidance, which is especially useful for ejector systems that need smooth, repeatable stroke behavior.
• General metal forming punch operations: Selecting M2 or A2 steel variants supports durable cutting performance for longer runs, while PS options can be chosen for cost-effective fabrication where wear demand is moderate.

Metric shank sizing and the provided D (5–32 mm) range make it straightforward to match common die layouts.

Available steels are PS, M2, and A2, selected to balance hardness, wear resistance, and toughness for punch blank service. For high-wear punch applications, M2 (high-speed steel) is typically chosen for strong wear resistance under cutting action; A2 is often selected when you need a tough tool steel with good dimensional stability after heat treatment.

• M2: Generally suited for tougher wear conditions; heat treated to a high hardness level for cutting durability (commonly in the mid-to-high HRC range depending on supplier process).
• A2: Usually hardened and tempered or quenched/tempered to achieve high hardness while maintaining improved toughness compared with very brittle grades.
• PS: A lower-alloy option used when cost and ease of fabrication matter, providing adequate performance for moderate wear demands.

In practice, hardness and wear resistance improve with higher-carbide/appropriate heat treatment, but increased hardness can reduce impact toughness—so select the grade that matches your loading and expected cycles.

To select the correct ejector punch blank, match the shank diameter (D) and the overall length (L) to your die’s punch guide and support requirements. This series covers D = 5–32 mm, so choose the diameter that fits your punch bore/guide size with the intended clearance for sliding guidance.

• Choose diameter (D): Select the exact size within 5 ~ 32 mm to align with your guide bushing or locating features.
• Choose length (L): Length options are provided as ranges: 40–100 mm, 50–100 mm, 56–100 mm, and 63–100 mm. Pick the minimum length that provides required working stroke coverage plus safe overtravel margins.
• Account for center dowel hole referencing: Ensure the dowel hole alignment interfaces correctly with your die spotting/guidance scheme so punch positioning remains repeatable.

Use your mold’s guide tolerances to confirm fit; tighter guidance improves alignment but increases risk of binding if clearances are too small.