The Dormer Pramet C139 5.5mm slot drill is a two-flute, standard-length tool designed for precise slot milling, shoulder milling, and ramping. With a 6mm Weldon shank and TiCN-coated HSS-E substrate, it delivers dependable performance across common machine shop materials.

• Diameter: 5.5 mm
• Length of cut: 13 mm
• Overall length: 57 mm
• Shank type: 6 mm Weldon shank with flatted section for secure seating
• Flutes: 2
• Coating: TiCN on powder-metallurgical HSS-E for wear resistance
• Helix angle: 30°
• Rake angle: 12°
• DIN standard: 844 K
• Primary uses: Shoulder milling, slot milling, ramping
• Material compatibility: Free-machining steel, plain carbon and alloy steel, cast iron, copper/copper alloys, titanium/titanium alloys

The TiCN coating reduces tool wear and lowers friction, extending life in demanding slots and passes. The powder-metallurgical HSS-E substrate blends toughness with high wear resistance, making it reliable for everyday milling tasks. The two-flute geometry supports efficient chip evacuation and stable engagement in slotting, while the 30° helix and 12° rake angle help minimize cutting forces for smoother finishes. The flatted Weldon shank prevents rotation in the holder, ensuring secure, repeatable performance on long workpieces.