CMT Hinge Boring Bit 28 x 57.5mm Right-Hand by CMT is a precision-engineered boring bit designed specifically for drilling flat-bottom hinge cup holes in cabinet doors, face frames, and panel components. Built for European-style concealed hinge installation, this 28mm diameter bit delivers clean, accurate results in solid hardwood, softwood, chipboard, MDF, and plywood. The parallel shank with driving flat and length adjusting screw makes it compatible with boring machines equipped with adaptors or chucks, giving woodworkers and cabinetmakers a reliable tool for high-volume hinge cup drilling.

Key Features

• HW (Tungsten Carbide) Cutting Head with Precision Balanced Centre Point - the carbide construction stays sharp longer under demanding production conditions, and the balanced centre point ensures accurate hole placement every time, reducing the risk of blowout or drift.
• 2 HW Precision Ground Cutting Edges (Z2) - dual carbide cutting edges work together to produce a smooth, consistent flat-bottom bore essential for seating European concealed hinges correctly.
• 2 Negatively Ground Spurs (V2) - the negatively ground geometry scores the material cleanly before cutting, minimizing tearout on the bore wall and producing a cleaner exit in panel materials like MDF and chipboard.
• Super-Strength Steel Body with PTFE Coating - the cutter portion is coated with orange or black PTFE, which resists pitch and resin buildup during continuous operation, reducing friction and extending the working life of the bit.
• Parallel Shank (10 x 26mm) with Driving Flat and Length Adjusting Screw - the standardized shank design seats securely in boring machine adaptors or chucks, and the length adjusting screw allows precise depth setting without guesswork.
• Right-Hand Rotation (RH) - designed for standard right-hand rotation spindles found on most multi-spindle CNC boring machines, boring centers, and drill presses, ensuring direct compatibility with common equipment configurations.

Why This Product

• The 28mm diameter and 57.5mm total length match the standard specifications required for European concealed hinge cup installation - making this bit a direct fit for cabinetmaking and panel processing workflows without adapting or modifying tooling.
• The combination of 2 precision ground HW cutting edges and 2 negatively ground spurs means the bit handles both cutting and scoring in a single pass, which is especially valuable when boring through melamine-faced chipboard or veneered MDF where surface quality matters.
• The PTFE coating on the cutter portion actively resists resin, pitch, and adhesive buildup during repetitive drilling cycles, reducing the frequency of cleaning stops and helping maintain consistent hole quality across large production runs.
• Compatibility with boring machines equipped with adaptors or chucks gives this bit broad machine compatibility, so it integrates into existing shop setups - from stand-alone boring machines to CNC boring centers - without requiring specialized toolholders.

Specifications

• Manufacturer Part Number: 317.280.11
• Brand: CMT Orange Tools
• Diameter: 28mm
• Total Length: 57.5mm
• Shank: 10 x 26mm
• Rotation: Right-Hand (RH)
• Number of Spurs: 2
• Number of Teeth: 2
• Tooth Sharpening: Negatively ground spurs
• Material: HW (Tungsten Carbide)
• Product Type: Hinge Boring Bit

Approved Applications

• Drilling flat-bottom hinge cup holes for European concealed hinge installation
• Cabinet door hinge cup boring
• Face frame hinge mounting preparation
• Panel processing in solid hardwood, softwood, chipboard, MDF, and plywood