The CMT Hinge Boring Bit 30 x 57.5mm Left-Hand (LH) is a precision carbide-tipped boring bit engineered for drilling clean, flat-bottom hinge cup holes in cabinet doors, face frames, and panel components. Designed for use on boring machines equipped with adaptors or chucks, this 30mm diameter bit delivers the flat-bottom bore geometry required for European-style concealed hinge installation. With a left-hand rotation and two precision-ground carbide cutting edges, it produces accurate, splinter-free results in solid hardwood, chipboard, MDF, and plywood applications.

Key Features

• Tungsten Carbide (HW) Cutting Head - the carbide-tipped head maintains a sharp, consistent edge through repeated use in demanding production environments, reducing downtime from frequent tool changes.
• Precision-Balanced Centre Point - the HW centre point registers the bit accurately on the workpiece, preventing walking at the start of the bore and producing precisely positioned hinge cup holes every time.
• 2 Precision-Ground HW Cutting Edges (Z2) - dual carbide cutting edges share the cutting load evenly, resulting in a flat, smooth bore bottom that meets the seating requirements of European concealed hinges.
• 2 Negatively Ground Spurs (V2) - the negatively ground spur geometry scores the material perimeter cleanly before the cutters remove the waste, delivering tear-out-free bore walls in veneered panels and laminates.
• Super-Strength Steel Body with PTFE Coating - the cutter portion is coated with orange or black P.T.F.E., reducing friction and preventing pitch and glue buildup on the tool so it runs cooler and cleans up faster.
• Parallel Shank (10 x 26mm) with Driving Flat and Length Adjusting Screw - the shank design provides a secure, slip-free grip in adaptors or chucks and allows precise depth adjustment, ensuring consistent bore depth across all spindles.
• Left-Hand (LH) Rotation - engineered specifically for left-hand spindle positions on multi-spindle boring machines, ensuring the bit rotates in the correct direction for clean cutting rather than rubbing.

Why This Product

• The 30mm bore diameter matches the standard cup size required for European concealed hinges, making this bit a direct-fit solution for cabinet door hinge boring without any modification or custom setup.
• The flat-bottom bore geometry - produced by the dual HW cutting edges and precision centre point - meets the seating geometry that European concealed hinges demand, so hinges mount flush and function correctly from the first install.
• The parallel shank with a driving flat and length adjusting screw allows repeatable depth setting across a multi-spindle machine, which matters in high-volume cabinet production where every cup hole must be identical.
• The PTFE-coated body and negatively ground spurs work together to reduce chip adhesion and panel tearout, keeping cut quality high throughout a production run on chipboard, MDF, plywood, and hardwood.

Specifications

• Manufacturer Part Number: 317.300.12
• Brand: CMT Orange Tools
• Diameter: 30mm
• Total Length: 57.5mm
• Shank: 10 x 26mm
• Rotation: Left-Hand (LH)
• Number of Spurs: 2
• Number of Teeth: 2
• Spur Geometry: Negatively ground spurs
• Material: HW (Tungsten Carbide)
• Product Type: Hinge Boring Bit

Approved Applications

• Drilling flat-bottom hinge cup holes in cabinet doors and face frames
• European concealed hinge installation
• Panel processing on boring machines equipped with adaptors or chucks
• Hinge boring in solid hardwood, softwood, chipboard, MDF, and plywood