CMT Hinge Boring Bit 26 x 57.5mm Left-Hand Rotation by CMT is a precision-engineered boring bit designed for drilling flat-bottom hinge cup holes used in European-style concealed hinge installations on cabinet doors and face frames. Built with a tungsten carbide (HW) cutting head and a super-strength steel body coated with P.T.F.E. to resist pitch and resin buildup, this left-hand rotation bit delivers clean, accurate bores in solid wood, chipboard, MDF, and plywood. Sized at 26mm diameter with a 57.5mm total length and a 10x26mm parallel shank with a driving flat and length adjusting screw, this bit is compatible with boring machines equipped with adaptors or chucks for high-volume cabinetry and panel processing workflows.

Key Features

• Tungsten carbide (HW) cutting head with precision balanced centre point - maintains accurate bore placement hole after hole, reducing tearout and rework in production environments.
• 2 precision ground HW cutting edges (Z2) - sharp, durable edges produce clean, flat-bottomed holes exactly as required by European concealed hinge standards.
• 2 negatively ground spurs (V2) - score the perimeter of the bore cleanly before the cutters engage, resulting in crisp, chip-free hole walls in hardwood, softwood, MDF, and chipboard.
• Super-strength steel body with P.T.F.E. coating on the cutter portion - the orange or black P.T.F.E. coating prevents pitch and glue buildup, extending tool life and reducing cleaning time between uses.
• Left-hand (LH) rotation - designed for use on left-hand spindle positions common in multi-spindle boring machines, ensuring correct cutting geometry and clean bore walls on those stations.
• Parallel shank (10x26mm) with driving flat and length adjusting screw - provides secure, repeatable seating in adaptors or chucks, allowing precise depth adjustment and minimizing runout during high-cycle boring operations.

Why This Product

• The 26mm diameter flat-bottom geometry is the exact bore size required by the majority of European concealed hinges, making this bit a direct match for cabinet door and face frame hinge cup drilling without modification or compromise.
• The combination of a precision balanced HW centre point and negatively ground spurs means the bit self-centers accurately and scores the material perimeter before cutting - reducing splintering in veneered chipboard and MDF where surface quality is critical.
• The P.T.F.E.-coated super-strength steel body resists resin and adhesive buildup that can slow cut speed and degrade finish quality in production runs, keeping the bit performing consistently over extended use.
• The left-hand rotation designation makes this bit a specific and necessary component for multi-spindle CNC boring machines and boring centers where left-hand spindle stations require a purpose-built LH bit - it cannot be substituted with a standard right-hand bit without sacrificing cut quality.

Specifications

• Manufacturer Part Number: 317.260.12
• Brand: CMT Orange Tools
• Diameter: 26mm
• Total Length: 57.5mm
• Shank: 10x26mm
• Rotation: Left-Hand (LH)
• Number of Cutting Edges: 2
• Number of Spurs: 2
• Spur Geometry: Negatively ground spurs
• Material: HW (Tungsten Carbide) head on super-strength steel body
• Coating: P.T.F.E. (orange or black) on cutter portion
• Product Type: Hinge Boring Bit

Approved Applications

• Drilling flat-bottom hinge cup holes for European concealed hinge installation
• Cabinet door hinge boring on solid hardwood and softwood
• Hinge cup drilling in chipboard, MDF, and plywood panels
• Face frame hinge mounting in cabinet production
• Left-hand spindle positions on multi-spindle CNC boring machines and boring centers
• Boring machines equipped with adaptors or chucks