CMT 310.040.22 Dowel Drill 4 x 20 x 57.5mm Left-Hand by CMT is a solid carbide boring bit engineered for precision dowel hole drilling in furniture manufacturing, cabinet making, and panel processing applications. Built entirely from premium super-micrograin carbide sourced from Ceratizit, this left-hand rotation drill delivers exceptionally clean, flat-bottom blind bores in hardwood, particle board, MDF, veneered panels, and other difficult composites - making it a reliable choice for high-speed boring units and CNC routing centers where consistent hole quality and extended tool life are critical.

Key Features

• Solid super-micrograin carbide (HWM) construction - provides outstanding wear resistance and allows an almost infinite number of resharpenings, reducing long-term tooling costs compared to standard bits.
• Curved, negatively ground spurs (2 spurs) - produce exceptionally clear bore walls and flat-bottom holes with no rough edges or tearout, ensuring clean dowel joint fit-up without secondary finishing.
• Balanced centre point - guarantees accurate hole placement and prevents the bit from wandering at entry, which is essential for tight-tolerance dowel alignment in furniture and cabinet assembly.
• Plunge edge extending to the centre of the bit - reduces drilling resistance and increases production speed, allowing faster feed rates on multi-spindle boring machines and CNC boring centers.
• 2 cutting edges (Z2) with 2 spiral flutes - efficiently evacuate chips from the bore during blind hole drilling, keeping the cutting zone clear and maintaining hole quality through extended production runs.
• Larger-than-traditional cylindrical head - offers extreme resistance to prolonged use, so the bit maintains its geometry longer between resharpening intervals even under demanding production schedules.
• 10 x 25mm parallel shank with driving flat and adjustable screw length - ensures a secure, repeatable seating in multi-spindle boring machine chucks and CNC tool holders, preventing slippage during left-hand rotation cutting.
• Left-hand (LH) rotation - correctly matched for left-hand spindle positions on multi-spindle panel boring machines, ensuring the cutting geometry engages material in the proper direction for clean bore entry and exit.
• Extreme sharpening grade - indicates a higher-precision ground cutting geometry that delivers finer surface finish inside each bore, critical for dowel fit tolerance in quality furniture production.
• 4mm cutting diameter x 20mm cutting height x 57.5mm total length - compact short-series geometry suited for tight multi-spindle spacing on panel boring equipment without tool interference.

Why This Product

• For shops running left-hand spindle positions on multi-spindle CNC boring centers or panel processing equipment, this bit provides the correct LH rotation geometry in a 4mm diameter - a common dowel size - eliminating the need for special adapters or workarounds.
• The all-carbide construction means this bit holds its edge significantly longer than HSS alternatives when drilling abrasive materials like particle board, MDF, and coated panels, reducing downtime for tool changes in high-volume production environments.
• The negatively ground spur design addresses one of the most common quality complaints in dowel boring - torn or ragged bore edges - by producing clean, splinter-free entry and exit on veneered and laminated surfaces where appearance matters.
• Because the bit is a solid carbide unit rather than a tipped design, it can be resharpened repeatedly as a single piece, making it a cost-effective long-term investment for cabinet makers and furniture manufacturers who depend on consistent, repeatable hole quality shift after shift.

Specifications

• Manufacturer Part Number: 310.040.22
• Brand: CMT Orange Tools
• Diameter: 4mm
• Cutting Height: 20mm
• Total Length: 57.5mm
• Shank: 10 x 25mm (parallel shank with driving flat and adjustable screw length)
• Rotation: Left-Hand (LH)
• Number of Cutting Edges: 2
• Number of Spiral Flutes: 2
• Number of Spurs: 2
• Blade Material: HWM - solid super-micrograin carbide
• Sharpening Grade: Extreme

Approved Applications

• Blind hole drilling for dowel connections in furniture manufacturing
• Panel drilling on multi-spindle boring machines
• Cabinet making and case goods production
• CNC boring center operations
• High-speed boring unit production runs
• Drilling hardwood, softwood, particle board, MDF, HDF, plywood, veneered panels, and coated composites