CMT 314.080.22 Dowel Drill for Through Holes - 5/16" x 40 x 70mm Left-Hand is a solid carbide boring bit engineered for clean, precise through-hole drilling in furniture panels, cabinet components, and composite sheet materials. Built entirely from premium super-micrograin carbide sourced from Luxembourg, this left-hand rotation drill delivers the chip clearance, bore quality, and durability demanded by high-production CNC boring centers and multi-spindle boring machines. Whether you are processing MDF, chipboard, hardwood, or veneered panels, this bit is designed to hold up under continuous industrial use while producing smooth, blowout-free exit holes every cycle.

Key Features

• Solid super-micrograin carbide body (HWM) - the entire bit is constructed from one piece of premium carbide, providing exceptional wear resistance and allowing an almost infinite number of resharpenings, extending the tool's usable life far beyond conventional steel bits.
• Curved, negatively ground spur tip design - produces exceptionally clean bore walls and splinter-free exit holes with no rough edges, reducing sanding and finishing time on finished panels.
• Centre-point balanced geometry - keeps the drill on target from the first contact, preventing wandering and ensuring consistent hole placement critical to dowel joint accuracy.
• Plunge edge running all the way to centre - reduces drilling resistance and increases production speed, allowing faster feed rates without sacrificing hole quality.
• 2 precision-ground cutting edges (Z2) with 2 spiral flutes - double-angle geometry and twin flutes evacuate chips efficiently, preventing clogging and reducing heat buildup during sustained high-speed operation.
• Cylindrical head larger than traditional tip designs - offers greater resistance to deflection and prolonged use, maintaining accuracy longer between tool changes on busy production lines.
• 10 x 26mm parallel shank with driving flat and adjustable screw length - fits standard industrial boring machine chucks and CNC tool holders securely, preventing slippage under load.
• Left-hand (LH) rotation - specifically designed for left-hand spindle positions on multi-spindle boring machines, ensuring correct chip ejection direction and clean bore entry on the correct face of the panel.
• Extreme sharpenability rating - the solid carbide construction supports repeated professional resharpenings, keeping the cost-per-hole low over the tool's lifetime.

Why This Product

• Purpose-built for through-hole dowel drilling at 5/16" diameter - with a 35mm cutting height and 70mm total length, this bit is sized to drill clean through panels up to approximately 30mm thick while maintaining sufficient clearance for chip evacuation, making it a natural fit for standard furniture panel thicknesses.
• Left-hand rotation makes it irreplaceable - not interchangeable - on multi-spindle CNC boring centers, left-hand and right-hand spindles require matched rotation bits. Using the correct LH version ensures proper chip flow, bore quality, and spindle load balance, which right-hand bits simply cannot replicate in this position.
• Performs across the full range of panel materials - the solid carbide construction and precision spur geometry handle hardwood, softwood, chipboard, MDF, HDF, plywood, laminates, and coated panels, eliminating the need for material-specific bit changes in mixed-production environments.
• Excellent performance on high-speed boring units and CNC routers - the geometry and carbide grade are matched for the spindle speeds and feed rates common to CNC panel processing, making this a reliable production tool rather than a general-purpose drill.

Specifications

• Manufacturer Part Number: 314.080.22
• Brand: CMT Orange Tools
• Diameter: 5/16"
• Cutting Height: 35mm
• Total Length: 70mm
• Shank: 10 x 26mm (parallel shank with driving flat and adjustable screw length)
• Number of Cutting Edges: 2
• Number of Flutes: 2 spiral flutes
• Rotation: Left-Hand (LH)
• Body Material: HWM - solid super-micrograin carbide
• Sharpening Rating: Extreme
• Tip Geometry: "V" Point 60 deg. sharpening (per series specification)

Approved Applications

• Through-hole drilling for dowel joint connections in panel furniture
• CNC multi-spindle boring center panel processing
• Cabinet and furniture component manufacturing
• High-speed boring of chipboard, MDF, HDF, and composite panels
• Through-hole boring in hardwood and veneered wood panels
• Laminate and coated panel through-hole drilling
• CNC router boring operations