CMT 378.082.12 Dowel Drill with Countersink for Through Holes is a left-hand rotation, tungsten carbide-tipped boring bit engineered for drilling, countersinking, and through-penetration in a single pass. Designed for use on multi-spindle CNC boring machines, CNC boring centers, and panel processing equipment, this 5/16" diameter through-hole dowel drill delivers clean, precise bores in chipboard, MDF, HDF, plywood, hardwood, softwood, laminates, and coated panels. With its 2-flute, 2-spur geometry and 60 deg. through-hole sharpening angle, the bit is purpose-built for high-productivity cabinet and furniture panel boring applications where consistent hole quality and long tool life are essential.

Key Features

• Tungsten Carbide (HW) Construction - carbide-tipped cutting edges maintain sharpness through demanding production runs in abrasive sheet goods like MDF, chipboard, and coated panels, reducing downtime for tool changes.
• Through-Hole with Countersink Geometry - drills, countersinks, and penetrates completely in one plunge, eliminating secondary operations and improving cycle times on CNC boring centers and panel lines.
• 60 deg. Through-Hole Sharpening Angle - optimized point geometry for clean entry and exit on through-penetration boring, minimizing tearout on both faces of the panel for a finished result without additional cleanup.
• Left-Hand (LH) Rotation - matched specifically to left-hand spindle configurations on multi-spindle boring machines, ensuring proper cutting action and chip evacuation for consistent hole quality.
• 2 Spurs and 2 Cutting Flutes - precision-ground spurs score the perimeter of the bore before the flutes clear material, producing clean bore walls and sharp hole edges in both face and edge drilling applications.
• 25/64" Shank (10x20mm) - robust shank diameter provides solid tool retention in CNC chuck or adapter collets, reducing vibration and runout that can compromise hole accuracy over long production cycles.
• 35mm Cutting Height with 29mm Inner Cutting Height - sufficient flute length to handle the full depth of standard cabinet and furniture panel stock, delivering clean through-penetration without deflection.
• 70mm Total Length - compact overall length keeps the tool rigid and stable in the spindle, supporting accurate, repeatable boring across large batch runs.

Why This Product

• The combined drill-and-countersink through-hole design completes multiple machining steps in a single plunge - ideal for production environments where speed and panel throughput matter, without sacrificing hole quality.
• Tungsten carbide (HW) cutting material is specifically suited to abrasive engineered wood products like MDF, HDF, chipboard, and laminates, making this bit a dependable choice for furniture and cabinetry panel processing lines.
• Left-hand rotation is a precise specification match for LH spindle positions on multi-spindle CNC boring machines and boring centers - selecting the correct rotation prevents premature wear and ensures the geometry cuts rather than rubs.
• The 5/16" diameter (approximately 8mm) is a standard dowel bore size for furniture fittings and panel assembly systems, making this bit a practical drop-in solution for common cabinet production workflows.

Specifications

• Manufacturer Part Number: 378.082.12
• Brand: CMT Orange Tools
• Diameter: 5/16"
• Cutting Height: 35mm
• Cutting Height I1: 29mm
• Total Length: 70mm
• Shank: 10x20mm (25/64" x 25)
• Tooth Geometry: Through holes 60
• Number of Spurs: 2
• Number of Teeth: 2
• Rotation: Left-hand (LH)
• Blade Material: HW (Tungsten Carbide)
• Product Type: Through-Hole Dowel Drill with Countersink

Approved Applications

• Chipboard
• MDF (Medium Density Fiberboard)
• HDF (High Density Fiberboard)
• Hardwood
• Softwood
• Plywood
• Laminates
• Coated Panels

Compatible Machines

• Multi-Spindle CNC Boring Machine
• CNC Boring Center
• Panel Processing Center
• Boring Machine with Adapter or Chuck