CMT Dowel Drill for Blind Holes - 8mm x 38.5mm Left-Hand Rotation by CMT is a specialty carbide-tipped boring bit engineered for drilling precise flat-bottom blind holes used in European concealed hinge cup installation and cabinet door hinge mounting. With a 5/16 in. cutting diameter, a 10x18mm shank, and left-hand (LH) rotation, this dowel drill is purpose-built for use with multi-spindle hinge boring heads - including compatibility with BLUM, SALICE, HAFELE, and HETTICH hinge boring head systems such as the CMT334 Universal Hinge Boring Head. It handles solid hardwood, chipboard, MDF, and plywood with clean, tearout-free results.

Key Features

• Left-Hand (LH) Rotation - designed specifically for left-hand spindle positions on multi-spindle boring heads and CNC boring machines, ensuring proper cutting direction and clean hole walls without fiber pullout on the leading edge.
• 8mm Cutting Diameter x 18mm Cutting Height - matches the exact geometry required for standard European concealed hinge cup holes, eliminating guesswork and delivering consistent, on-spec blind holes every time.
• Tungsten Carbide (HW) Tip Construction - hard carbide cutting edges bonded to a high-strength steel body deliver long service life in demanding production environments including chipboard, MDF, and hardwood applications.
• 2 Spurs and 2 Cutting Teeth - precision-ground spurs score the perimeter of the hole ahead of the cutting teeth, producing flat-bottom blind holes with clean bore walls and no tearout on the face of the workpiece.
• 10x18mm Cylindrical Shank - the standardized shank diameter and length allows direct mounting into hinge boring heads and CNC point-to-point machine spindles without adapters in most configurations.
• 38.5mm Total Length - compact overall length keeps the bit rigid and minimizes deflection, supporting accurate, repeatable hole positioning across large production runs.
• Compatible with CMT334 Universal Hinge Boring Head - the three-spindle CMT334 boring head supports BLUM, SALICE, HAFELE, and HETTICH hinge formats, and this bit is a direct drop-in replacement or optional addition for that system.

Why This Product

• If your hinge boring head has a left-hand spindle position, this LH-rotation bit is the correct tool - using a right-hand bit in an LH spindle produces poor cut quality and accelerated wear. This bit solves that problem directly.
• The 8mm cutting diameter and 18mm cutting height match the geometry demanded by BLUM, SALICE, HAFELE, and HETTICH concealed hinge systems, making it a reliable fit for cabinet shops working across multiple hinge brands.
• Carbide (HW) construction handles the abrasive demands of chipboard and MDF - materials that quickly dull standard high-speed steel bits - extending tool life in high-volume production settings.
• At 38.5mm total length with a 10x18mm shank, this bit fits the standardized spindle geometry of multi-spindle CNC boring machines and hinge boring heads, reducing setup time and maintaining consistent hole depth from part to part.

Specifications

• Manufacturer Part Number: 393.080.12
• Brand: CMT Orange Tools
• Diameter: 5/16 in. (8mm)
• Cutting Height: 18mm
• Total Length: 38.5mm
• Shank: 10x18mm
• Rotation: Left-Hand (LH)
• Number of Spurs: 2
• Number of Teeth: 2
• Blade Material: Tungsten Carbide (HW)
• Product Type: Dowel Drill for Blind Holes

Approved Applications

• Drilling flat-bottom blind hinge cup holes in cabinet components
• European concealed hinge installation (BLUM, SALICE, HAFELE, HETTICH compatible systems)
• Cabinet door hinge cup boring on panel processing centers and CNC boring machines
• Left-hand spindle position drilling on multi-spindle hinge boring heads
• Boring blind holes in solid hardwood, softwood, chipboard, MDF, and plywood