The Dormer Pramet C40 20.0mm HSS-E Flatted Shank Multi-Flute Roughing End Mill is a robust tool designed for efficient roughing in metalworking. Built for shoulder milling, slot milling, and ramping, it’s ideal for machinists working with free‑machining and plain carbon steels as well as copper and copper alloys.

• Diameter: 20.0 mm
• Cutting length: 38 mm
• Overall length: 104 mm
• Reach / neck relief: 53.5 mm
• Shank: Weldon 20 mm with flatted shank for secure seating
• Material: Cobalt-based HSS‑E (high‑speed steel with cobalt) for improved hot hardness
• Finish: Bright finish
• Flutes: 4-flute design for efficient material removal
• Profile: NF flat coarse pitch for consistent roughing
• Helix angle: 30° for effective chip evacuation
• Rake angle: 12° to aid shoulder milling and reduce rubbing
• Standards: DIN 844 K compatible
• Applications: Shoulder milling, slot milling, and ramping in free‑machining and plain carbon steel and copper/copper alloys

Designed for reliability and predictable performance, this end mill combines a proven 4‑flute geometry with a flatted Weldon shank to minimize runout and maximize clamping stability. The cobalt‑based HSS‑E material boosts high‑temperature performance during demanding roughing passes, while the NF flat coarse pitch profile helps maintain steady chip formation and smooth chip evacuation. With its precise dimensions and DIN 844 K compatibility, it integrates smoothly into standard toolholding setups, delivering consistent results across multiple milling operations.