Drill bit DORMER spiral with cylindrical shank, model 8211130720

Drill bit DORMER spiral with cylindrical shank, model 8211130720 is a general-purpose spiral twist drill designed for rotary drilling in workshop and industrial environments. The tool features a spiral flute geometry that removes chips efficiently and a cylindrical shank that fits securely in chucks and drill holders. It is intended for use in hand, bench, or machine drills where accuracy and reliable chip evacuation are required.

Advantages

The spiral flute design provides continuous chip clearance and stable cutting action, while the cylindrical shank ensures firm clamping and concentric rotation in most standard drill chucks. The drill bit's geometry balances cutting performance and versatility for a range of common drilling tasks. Its construction supports repeated use in production and maintenance settings with predictable drilling results.

Suitable for

• General-purpose drilling in metals compatible with high-speed and carbon steels
• Drilling in workshop hand drills and bench or pillar machines
• Maintenance, assembly, and fabrication tasks requiring through-holes or pilot holes

Key specifications

• Tool type: spiral twist drill with cylindrical shank
• Shank style: cylindrical for direct chuck or drill holder mounting
• Flute geometry: spiral flutes for chip evacuation
• Intended use: rotary drilling in hand, bench, or machine drills
• Application scope: general-purpose drilling in compatible materials

How to use

Secure the drill bit by inserting the cylindrical shank fully into the drill chuck or holder and tighten to ensure concentric clamping. Select appropriate spindle speed and feed rate for the material being drilled, and use cutting fluid or coolant where recommended to extend tool life and improve hole quality. Begin drilling with a steady feed, maintain alignment, and withdraw periodically if necessary to clear chips and prevent clogging.

Usage recommendations

Use matching drill speeds and lubrication for the material to minimise wear and reduce heat. Inspect the bit before use for wear or damage and replace when cutting performance declines. For precise hole diameter and surface finish, use proper clamping of the workpiece and consider pre-centering with a center punch or pilot drill.