Solid carbide spiral-flute twist drill bit set — 4 mm to 20 mm, 120 mm length Why this set helps you get the job done Precision and durability: Made from solid carbide for high hardness and wear resistance, delivering accurate, consistent holes and longer tool life compared with standard HSS bits. Cleaner, faster drilling: Spiral flute twist design evacuates chips efficiently during metal drilling, reducing clogging and improving drilling speed and hole quality. Easy handling and machine compatibility: Bright round shanks provide reliable insertion and centering in drill chucks and drilling machines for steady, repeatable performance. Versatile sizing for common metalwork: The set covers a 4 mm to 20 mm range, with 120 mm bit length for deeper holes or through-material applications. The 5.2 mm bit in the set is highlighted for common metalworking tasks. How it solves common problems Reduces breakage and rework by using a harder material that resists wear and deformation under load. Minimizes chip buildup and heat by promoting continuous chip removal, which helps maintain cutting edge life and hole accuracy. Simplifies setup and improves concentricity thanks to the bright round shank that fits standard chucks cleanly. Typical applications Fabrication and assembly: Drilling accurate holes for fasteners, fittings, or locating pins in metal components. Maintenance and repair: Reworking machine parts, replacing worn holes, or creating mounting holes on-site with consistent results. Metalworking and shop use: Producing holes in metal panels, brackets, and parts where repeatable precision and durability are required. Key specifications Material: Solid carbide Size range: 4.0 mm to 20.0 mm Length: 120 mm Shank type: Bright round shank Flute design: Spiral flute twist for chip evacuation Notable item: Includes a 5.2 mm drill bit suitable for a variety of metalworking applications What to expect in use Stable centering in drill chucks and drilling machines Efficient chip removal and reduced heat buildup during metal drilling Durable cutting edges for repeated, precise holes If you need reliable carbide bits for metal drilling with a wide size range and longer reach, this set provides hardness, precision, and chip-control features suited to production, shop, and maintenance work.