Three-Edge Roughing Spiral Mill VHM from the SF51 Series 

Index: SF51.18.055.110.18XR

Industrial spiral mill made of sintered carbide (VHM) from the SF51  series with a negative construction (chip ejection downwards). Designed for efficient rough machining, cutting, and grooving on CNC machining centres and overhead milling machines. The left-handed screw line (negative) presses the material to the work table, eliminating the risk of tear-outs on the upper edge of the workpiece. Three spiral cutting edges with a profiled chip breaker reduce cutting resistance, lower spindle load, and effectively dampen vibrations during intensive cutting. The ground shank in the H6 accuracy class protects the drive system and ensures high stability of the process.

Key technical parameters and properties:

• Three-Edge Roughing Design Z3 (Negative): Dedicated roughing profile with downward chip ejection presses the workpiece against the table and ensures a perfectly finished, clean upper edge.
• Premium Class Sintered Carbide Monolith (VHM): Rigid monolithic construction minimizes tool deflection under load and guarantees high mechanical durability.
• Geometry with Chip Breaker: Splits the machined material into smaller fragments, reducing cutting resistance and stabilising the system's operation.
• Optimised Shank Roughness: The shank surface features low roughness (Ra ≤ 0.3 µm), preventing slipping in the holder and protecting the spindle taper from wear.
• Dynamic Balancing in Class G2.5: Static-dynamic balancing in accordance with ISO/EN standard (class G2.5) eliminates vibrations at maximum rotational speeds.
• Advanced Protective Coating NaDia (Series .XR): Black PVD coating with extreme hardness of 3650 HV and very low friction coefficient (0.01–0.05) applied at low temperatures. Drastically increases the edge's wear resistance, prevents material sticking, and significantly extends tool life during machining of wood, laminates, plywood, plastics, and aluminium.