Kemmler SK Whistle Notch End Mill Holders (DIN 1835-E)

Available Sizes and Part Numbers

Purpose and Application

Kemmler Whistle Notch holders (DIN 1835-E) are designed for use on CNC milling machines and machining centers with SK 40 and SK 50 spindles acc. to ISO 7388-1 (DIN 69871). They are used for clamping solid carbide and indexable end mills, drills, and boring tools with DIN 1835 Form E cylindrical shanks. Unlike Weldon systems, the Whistle Notch shank features a 2° inclined clamping flat, enabling precise axial tool presetting using an adjusting screw.

Design and Features

The clamping screw transfers force onto the inclined flat, pressing the tool both radially against the bore wall and axially against the stop screw. This completely eliminates tool pullout under heavy axial loads. The bore is manufactured to H4 tolerance. Radial runout is ≤ 3 µm, and the hardened body is dynamically balanced to G 2.5 at 25,000 rpm. Includes a bore for an RFID chip.

Compatibility

Tooling is compatible with machine spindles featuring SK 40 and SK 50 tapers (ISO 7388-1 / DIN 69871). Designed for DIN 1835 Form E shanks from 6 mm to 40 mm diameter. Retention knobs acc. to ISO 7388-3 (DIN 69872) are used for spindle mounting.

Selection Parameters

Selection is based on spindle taper SK (40, 50) and clamping diameter DCONWS (6 to 40 mm). Standard gage lengths LPR range from 50 mm to 120 mm.

Key Advantages:

• Anti-Pullout & Presetting: 2° inclined flat combined with stop screw ensures rigid clamping and length presetting.
• Precision Accuracy: Ground H4 bore tolerance with runout ≤ 3 µm.
• High-Speed Balancing: G 2.5 at 25,000 rpm protects the spindle assembly against vibration.
• Durable Construction: Case-hardened alloy steel ensures bore longevity under frequent tool changes.