The Dormer Pramet C135 4.0mm HSS-E slot drill is a precise, robust tool designed for accurate slot milling in steel and copper alloys. Built for professionals who need dependable performance in shallow to mid-depth slots, it combines high-edge durability with thoughtful geometry for consistent results.

• Diameter: 4.0 mm
• Length of Cut: 11 mm
• Overall Length: 63 mm
• Reach / Neck Relief: 27 mm
• Shank: 6 mm Weldon shank with flatted surface for secure seating
• Shank Type: Flatted (flat) shank design
• Material: HSS-E cobalt-based steel
• Finish: Bright finish
• Helix: 30°
• Rake Angle: 12°
• Flutes: 2
• Application: Slot milling in free-machining steel and copper/copper alloys
• Standards: Dormer standard alignment

Designed for reliability in production settings, this 2-flute slot drill delivers clean, accurate slots with strong wear resistance thanks to its HSS-E cobalt-based composition. The 30° helix and 12° rake reduce built-up edge and promote smooth chip evacuation, while the flatted 6 mm Weldon shank ensures secure, repeatable seating in collets and holders. With an 11 mm cutting length and 27 mm neck relief, it provides practical reach for shallow to mid-depth slots without compromising rigidity. Ideal for machinists working with free-machining steel and copper alloys, it helps achieve precise slot geometry and consistent performance across jobs.