CMT 375.080.12 4 Flute Dowel Drill for Through Holes - 5/16" x 2-3/4" LH is a precision-engineered left-hand rotation through-hole dowel drill from CMT, purpose-built for CNC boring machines and multi-spindle panel processing centers. With a 5/16" diameter, 40mm cutting height, and 70mm total length, this long-series boring bit is the right tool when drilling clean, consistent through-holes in chipboard, MDF, hardwood, softwood, plywood, and coated panels. The left-hand (LH) rotation design pairs with right-hand machine spindles to produce balanced, vibration-free cuts - ideal for cabinet assembly lines and furniture production environments where hole quality directly affects dowel fit and joint strength.

Key Features

• Tungsten Carbide (HW) Cutting Material - delivers long-lasting edge retention through abrasive engineered wood products like MDF, chipboard, and HDF, reducing the frequency of tool changes and downtime on production runs.
• Left-Hand (LH) Rotation - designed to work in left-hand spindle positions on multi-spindle CNC boring centers, ensuring correct chip ejection direction and clean hole entry from the correct face of the panel.
• Through-Hole 60 deg. Tooth Geometry - the 60 deg. point geometry is optimized specifically for drilling complete through-holes, producing clean entry and exit faces with minimal tearout on laminates and coated panels.
• 2-Flute Cutting Design with 40mm Cutting Height - the 40mm cutting height accommodates a range of panel thicknesses commonly used in cabinet and furniture production, giving you full through-hole capacity without repositioning.
• 10x20mm Shank - the substantial shank dimensions provide secure clamping in standard boring machine chucks and adapters, reducing runout and maintaining consistent hole diameter across all spindles.
• 70mm Total Length (Long Series) - the long-series body length gives adequate clearance for the spindle housing during boring operations, preventing interference on deep-reach or close-tolerance machine setups.

Why This Product

• If your CNC or multi-spindle boring machine requires left-hand spindle tooling, this drill fills that exact role - the LH rotation is not a secondary option but the primary design of this bit, so it integrates directly without adapters or workarounds.
• The 5/16" diameter and 40mm cutting height make this drill well-suited for standard dowel hole patterns in cabinet carcass panels, where consistent hole diameter and depth are critical for accurate dowel alignment during assembly.
• Tungsten carbide (HW) construction means this drill holds its edge significantly longer than high-speed steel alternatives when working through abrasive sheet goods like MDF and particleboard - reducing cost-per-hole over the life of the tool.
• The 70mm long-series body length provides the clearance needed for through-hole operations on panels where a shorter series drill would bottom out in the spindle housing before completing the cut.

Specifications

• Manufacturer Part Number: 375.080.12
• Brand: CMT Orange Tools
• Diameter: 5/16"
• Cutting Height: 40mm
• Total Length: 70mm
• Shank: 10x20mm
• Rotation: Left-hand (LH)
• Number of Teeth: 2
• Tooth Geometry: Through holes 60
• Blade Material: HW (Tungsten Carbide)
• Series: Through Hole Long Series (70mm)

Approved Applications

• Multi-Spindle CNC Boring Machine
• CNC Boring Center
• Panel Processing Center
• Boring Machine with Adapter or Chuck
• Chipboard and Particleboard Panels
• MDF and HDF Sheet Goods
• Hardwood and Softwood Panels
• Plywood
• Laminates and Coated Panels