Durable and precise, the Dormer Pramet C135 12.0mm HSS-E slot drill is designed for reliable slot milling in free‑machining steel and copper alloys. Built with a Weldon 12 mm shank and cobalt-based HSS‑E, it delivers consistent cuts in demanding workshop environments.

• Diameter: 12.0 mm
• Flutes: 2 flutes
• Length of cut: 26 mm
• Overall length: 110 mm
• Reach with neck relief: 64.5 mm
• Shank: Weldon 12 mm
• Material: HSS‑E cobalt-based (cobalt enriched high-speed steel)
• Finish: Bright finish
• Helix angle: 30°
• Rake angle: 12°
• Primary use: Slot milling in free‑machining steel and copper/copper alloys

This slot drill excels at creating clean, accurate slots with stable geometry. The 30° helix supports smooth chip evacuation and steady cutting action, while the 12° rake helps align the cutting edge for efficient material removal. The Weldon shank ensures secure seating in collets or endmill holders, reducing the risk of slip during deep slots. With its cobalt‑based HSS‑E composition, the tool resists wear in tougher materials, extending life for busy production runs. The long reach and neck relief enable deeper slotting without sacrificing rigidity, making it a reliable choice for both maintenance and fabrication workflows.