SKH51 Steel DLC Coated Short Shoulder Punches

Short shoulder punches with DLC coating are used in injection- and press-adjacent metal forming tools where punch guidance and dimensional repeatability directly affect part quality. The DLC (XCD) surface treatment helps reduce sliding wear and maintains stable penetration behavior over repeated cycles, while the single-stepped shank supports consistent positioning during tool assembly.

• Automotive connector/terminal forming: Ideal for blanking and piercing small features where controlled wear on the punch tip improves lifetime and helps keep burr and dimensional drift low.
• General-purpose die sets: Suited for standard die block layouts that require a reliable seating/locating fit; the stepped shank promotes accurate die setup and repeatable forming operations.
• Thinner material piercing: The optimized short-shoulder geometry supports predictable guidance under load, which is beneficial for maintaining hole location and reducing shoulder rounding.

This punch series is available in SKH51 equivalent (M2) or SKH40 equivalent (powdered HSS). SKH51/M2 is a high-speed steel grade chosen for a balance of wear resistance and hot hardness, supporting repeatable press work under sliding contact.

• Surface treatment: DLC (XCD) coating for low-friction wear control; DLC + WPC for enhanced protection in more abrasive or higher-load environments.
• Hardness and trade-offs: High-speed steels like SKH51/M2 are typically used in a quenched-and-tempered or hardened state depending on tool requirements; compared with powdered HSS (SKH40), SKH51 is often selected when higher wear resistance and consistent performance are primary priorities.
• Wear vs. toughness: DLC improves wear and reduces friction, but ultimate edge life still depends on the steel’s toughness; heavier loading may favor the tougher option when available.

Note: Specific HRC values are not provided in the supplied data; confirm target hardness from your shop heat-treatment spec for best results.

Selection starts with matching the shank diameter D and the tip geometry to your die block and cavity/core requirements. Choose D from 3, 4, 5, 6, 8, or 10 mm and verify the shank tolerance is +0.005/0, m5 to ensure proper fit in the punch guide/holder.

• Tip length (B): Available as L or S; pick the version that provides the required working length without excessive unsupported stick-out.
• Tip dimension (P, W): Select P = 1 ~ 7 mm and W = 1 ~ 2.5 mm based on the required forming/clearance envelope for the cavity feature.
• Overall length (LC) and alteration: LC = 17 ~ 39.9 mm and related tolerances (LCT/LMT) follow the same 17 ~ 39.9 mm alteration range. Use LC to meet press tool stack-up and the desired projection.
• Tip corner R: R ranges from 0.15 up to 1.47/1.97/2.47/2.97/3.97/4.97 mm depending on the chosen geometry—align with your die radii to avoid stress concentration.

When in doubt, model the fixture fit using the m5 shank tolerance and verify guide clearance for repeatable punch centering.