Center Dowel Ejector Punches - Metric CRN Coating

Center dowel ejector punches are used in injection and die-casting tool sets where consistent part ejection must be synchronized with precise locating features. This metric punch variant is well-suited for tooling that cycles frequently, because the center dowel promotes repeatable alignment during travel and reduces the risk of side-loading.

In automotive and appliance insert die builds, these punches help maintain stable ejection of thin or complex parts by guiding the ejection motion through a defined center path. The CRN-coated working surface improves abrasion resistance, supporting stable performance as wear occurs at the sliding interface.

They are also effective in progressive die and multi-cavity mold assemblies where locating holes and ejector timing must stay consistent over long production runs. The available tip shapes and metric shank diameters allow matching the punch geometry to locating bushing and ejector clearance requirements.

• Use in die casting tool builds requiring durable wear resistance
• Best fit when central alignment is critical for stable ejection cycles
• CRN coating targets abrasion-driven wear at the punch working surface

The provided specification identifies this product as a CRN-coated center dowel ejector punch, but it does not list the base steel grade or numeric heat treatment state. Therefore, the material section focuses on coating-relevant performance and process considerations supported by the available data.

• CRN coating: Designed to improve wear resistance and abrasion tolerance at the punch contact surfaces during repeated ejection cycles.
• Wear vs. toughness trade-off: Coatings generally enhance surface hardness and reduce abrasive wear, while the underlying substrate must still provide sufficient toughness to resist chipping under side loads—alignment provided by the center dowel helps manage this.
• Manufacturing process (typical for coated ejector punches): precision turning/finishing of the shank and point, followed by coating deposition and controlled finishing to maintain geometry for locating fit.

If you need exact substrate hardness (HRC) or heat treatment (e.g., nitriding, quench & temper), the base material grade must be confirmed for this series.

Select dimensions by matching the punch’s shank diameter and overall length to the mold’s ejector stroke space and the locating system geometry. This series offers D (shank dia.) options of 10, 13, 16, 20, 25, and 32 mm, and a fixed L (length) range of 71 to 130 mm.

• Choose D to align with the die/mold locating feature size and the available guide bore/bushing ID clearance.
• Select L1 (point length) from 19–25 mm or 25–30 mm to ensure the working point reaches the required contact position without overtravel.
• Verify P (4–16 mm), W (4–10 mm), and R (0.2 up to 15.975 mm, depending on variant) to match the intended tip geometry for controlled ejection and part contact.

Tip shape is available in H, J, K, L, N, O, R, V, X, Y, Z; use the same tip profile across cavities to keep ejection force distribution consistent. For fit, account for coating thickness and finishing: confirm tolerances in your drawings against the chosen diameter and locating hole/bushing specs.