MISUMI Alpha Treatment Key Flat Shank Tapped Punches

Key flat shank tapped punches are used in precision die sets and injection mold tooling where a threaded, mechanically captured punch must maintain stable geometry through repeated cycles.

• Automotive connector and small-part dies: Apply these punches as ejector or locator-style elements in multi-cavity tooling. The strengthened, nanocrystallized surface supports wear resistance while the maintained toughness helps prevent chipping at the shank during high-frequency actuation.
• Electronics and appliance housings: Use for forming/parting features that rely on smooth feed and reliable lubrication retention. The microtexture reduces friction, helping punches glide consistently and improving oil retention during long production runs.
• General die work with tapped interfaces: Their tapped, key-style shank design suits common threaded punch applications where repeatable engagement and dimensional stability matter.

These Alpha Treatment variant characteristics are suited when you need surface strengthening to reduce wear but cannot afford a significant loss of toughness or dimensional change.

This series is available in two main steel options: SKD11 equivalent (D2) and SKH40 equivalent (powdered high-speed steel). Both are chosen to balance wear resistance and toughness for standard tapped punch duties.

• Alpha Treatment / nanocrystallized surface hardening: A nanocrystallized, microtexture-treated surface increases surface strength and wear resistance while minimizing dimensional change. This supports stable punch performance under sliding and lubrication conditions.
• SKD11 (D2 equivalent): Typically selected for strong wear resistance; it can be more sensitive to edge damage than tougher high-speed options if severely loaded.
• SKH40 (powdered HSS): Powdered metallurgy supports uniform carbide distribution, generally improving wear behavior while retaining toughness compared with some conventional high-carbon tool steels.

Because specific heat-treatment and hardness values are not provided in the input data, engineers should confirm target hardness (HRC) and any final heat-treatment state with the supplier documentation for the chosen material grade.

Select dimensions by matching the punch tip geometry to the mold die function (e.g., forming clearance, locating, or ejector-related engagement) and ensuring shank clearance through the die plate.

• Shank diameter (D): Choose from 6 ~ 25 mm based on the guide/bushing and holder bore. Confirm interference/clearance to avoid binding during reciprocation.
• Tip dimensions: Tip length B (L, S, X) and tip dimensions P (1.5 ~ 18 mm) with W (1.5 ~ 6 mm) must match the required working envelope at the cavity/core interface.
• Full length alteration (LC): Use the available LC ranges (27 ~ 79.9, 27 ~ 99.9, 32 ~ 99.9, 32 ~ 79.9) to fit your die stack-up and the protrusion needed for the tapped engagement.
• Corner radius (R): Tip corner R is fixed at 0.15 mm per the spec, which affects stress concentration at the feature corners.

For tolerance and fit, align the shank diameter D to the die-holder bore tolerance class used in your design standards. Tip dimension alteration values (PC 0.8 ~ 9, WC 0.8 ~ 3) indicate there may be controlled dimensional adjustment—verify how those alterations are handled for your cavity/core mating surfaces.