CMT Dowel Drill with Countersink - 5/16" Diameter, Left-Hand Rotation (376.081.12) by CMT is a precision-engineered boring tool designed to drill and countersink in a single pass on CNC boring machines and multi-spindle boring centers. The integrated countersink creates a clean, flush recess for bolt heads and panel connectors, eliminating the need for a secondary operation and improving throughput on panel processing lines. Built on a super-strength steel body with a tungsten carbide (HW) head, this left-hand rotation dowel drill delivers consistent, repeatable results in chipboard, MDF, hardwood, and coated panel applications.

Key Features

• Carbide (HW) Head with Precision Balanced Centre Point - the tungsten carbide cutting head stays sharp longer than high-speed steel alternatives, and the balanced centre point keeps the drill on-target at the start of each bore, reducing tear-out and runout in production environments.
• 2 Precision Ground Cutting Edges (Z2) - dual cutting edges share the load evenly, producing a clean, flat-bottomed hole with smooth side walls and extending tool life between resharpening cycles.
• 2 Negatively Ground Spurs (V2) - the negatively sharpened spurs score the panel surface cleanly before the main cutting edges engage, preventing chip-out and delamination on veneered, laminated, and coated panels.
• 2 Spiral Flutes with PTFE Coating - the spiral flutes evacuate chips efficiently while the orange or black PTFE coating on the spiral portion prevents pitch and glue buildup, keeping the tool running cleanly and reducing downtime for cleaning.
• Left-Hand (LH) Rotation - engineered specifically for left-hand spindle positions on multi-spindle CNC boring machines, ensuring the cutting geometry engages correctly and produces a burr-free exit on the face side of the panel.
• Parallel Shank with Driving Flat and Length Adjusting Screw (10x25mm) - the driving flat prevents slippage in the machine collet or chuck while the length adjusting screw allows precise depth setting, supporting repeatable countersink depth across a full production run.
• Integrated Countersink - combining drilling and countersinking into one tool and one pass reduces cycle time, minimizes tool changes, and keeps connector recesses consistent across every panel.

Why This Product

• For cabinet shops and panel processors running left-hand spindle positions, this drill fills a specific requirement - LH rotation with an integrated countersink - that standard right-hand boring bits cannot satisfy, making it a direct fit for multi-spindle CNC boring centers with alternating spindle orientations.
• The combined drill-and-countersink design cuts cycle time by performing two operations in a single plunge, which matters in high-volume panel processing where every second per bore adds up across thousands of parts.
• Negatively ground spurs paired with a carbide cutting head make this tool suitable for abrasive engineered materials like MDF, HDF, and melamine-coated chipboard - materials that rapidly dull standard steel bits and cause edge breakout without proper spur geometry.
• The PTFE-coated spiral reduces adhesive and pitch buildup during drilling, which extends the usable life of the tool between cleaning or resharpening intervals and lowers the cost per hole in glue-heavy or pre-glued dowel applications.

Specifications

• Manufacturer Part Number: 376.081.12
• Brand: CMT Orange Tools
• Diameter: 5/16"
• Cutting Height: 15mm
• Total Length: 57.5mm
• Shank: 10x25mm
• Rotation: Left-Hand (LH)
• Number of Flutes: 2
• Number of Spurs: 2
• Spur Sharpening: Negatively ground spurs
• Blade Material: HW (Tungsten Carbide)
• Tool Type: Dowel Drill with Countersink

Approved Applications

• Drilling and countersinking in one pass on CNC boring machines
• Bolt head and connector recessing in panel assemblies
• Chipboard panel processing
• MDF and HDF boring
• Hardwood and softwood dowel boring
• Plywood and laminated panel drilling
• Coated and veneered panel production