CMT Hinge Boring Bit 20 x 70mm Left-Hand Rotation by CMT is a long-series boring bit engineered for drilling precise flat-bottom hinge cup holes in cabinetry and panel components. Designed specifically for European-style concealed hinge installation, this 20mm diameter bit features a tungsten carbide (HW) cutting head, a PTFE-coated spiral for clean chip evacuation, and left-hand rotation to suit compatible multi-spindle boring machines and CNC processing centers. Whether you are boring hinge pockets in solid hardwood, MDF, chipboard, or plywood, this bit delivers the accuracy and edge quality that cabinet door hinge mounting demands.

Key Features

• Tungsten Carbide (HW) Cutting Head - Carbide-grade hardness maintains a sharp, consistent edge through high-volume production runs in both hardwood and engineered panel materials, reducing downtime for tool changes.
• PTFE-Coated Spiral Flutes - The orange or black P.T.F.E. coating on the spiral portion prevents pitch and glue buildup, keeping the flutes clear and extending the working life of the bit between sharpenings.
• Precision-Balanced Centre Point - The HW head includes a precision balanced centre point that locates the bore accurately before the cutting edges engage, eliminating wandering and ensuring repeatable hinge cup placement.
• Negatively Ground Spurs (2 spurs) - Negatively ground spurs score the material perimeter cleanly before the main cutting edges clear waste, producing flat-bottom holes with crisp, tear-out-free walls.
• 2 Precision Ground Cutting Edges (Z2) - Twin cutting edges balanced at Z2 geometry deliver a smooth flat bottom in each hinge cup, which is critical for flush-seating European concealed hinges.
• Left-Hand (LH) Rotation - Matched to left-hand spindle positions on multi-spindle CNC boring machines and boring centers, ensuring correct chip ejection direction and bore geometry without adaptation.
• Parallel Shank with Driving Flat and Length Adjusting Screw - The 10 x 26mm parallel shank includes a driving flat and length adjusting screw for secure, slip-free clamping and fast depth adjustment in boring machine chucks or adapters.
• Super-Strength Steel Body - The high-strength steel shaft resists flex and vibration at boring speeds, maintaining bore position accuracy even in demanding panel processing applications.

Why This Product

• The 70mm total length makes this a long-series option, suitable for reaching hinge cup positions in thicker cabinet door components where standard-length bits cannot achieve the required depth without repositioning.
• Left-hand rotation is not an afterthought - it is built into the bit's geometry from the cutting edges to the spiral flute direction, making it the correct tool for LH spindle positions rather than a workaround.
• The combination of a precision-balanced carbide centre point, negatively ground spurs, and Z2 cutting edges addresses the three critical requirements of hinge boring in one tool: accurate location, clean entry, and a flat cup bottom.
• PTFE spiral coating reduces adhesion of resins and adhesives common in chipboard and MDF panels, helping maintain consistent bore quality across long production runs without frequent cleaning interruptions.

Specifications

• Manufacturer Part Number: 369.200.12
• Brand: CMT Orange Tools
• Diameter: 20mm
• Total Length: 70mm
• Shank: 10 x 26mm
• Rotation: Left-Hand (LH)
• Number of Spurs: 2
• Number of Teeth: 2
• Tooth Geometry: Negatively ground spurs
• Material: HW (Tungsten Carbide)
• Product Type: Hinge Boring Bit

Approved Applications

• Drilling flat-bottom hinge cup holes in cabinet components
• European concealed hinge installation
• Cabinet door hinge mounting
• Panel boring in solid hardwood, softwood, chipboard, MDF, and plywood