CMT Solid Carbide Straight Bit Long Series - 1/8 in. Cutting Diameter, 1/4 in. Shank is a precision-ground routing bit engineered for deep, narrow grooves and detail work where a standard-length straight bit simply cannot reach. Built from solid tungsten carbide, this long-series bit delivers the rigidity and cutting endurance needed for grooving door and window frames, weatherseal channels, and fine inlay work. The 1/8 in. cutting diameter and 1/2 in. cutting height make it the go-to choice for re-grooving frames to accept wind-blocking weatherseal inserts, helping improve energy efficiency in older homes. With a right-hand rotation and 2-flute design, it produces clean, consistent cuts in a wide range of materials.

Key Features

• Solid Tungsten Carbide Construction - the entire bit body is made from solid carbide (HWM material grade), giving it exceptional strength and resistance to deflection during deep cuts, so you get straighter, cleaner grooves without the risk of breakage.
• Long Series Design - 2 in. Total Length - the extended overall length allows the bit to reach deeper into frames and channels that shorter bits cannot access, expanding the range of routing tasks you can complete with a single setup.
• 1/2 in. Cutting Height - delivers up to 1/2 in. of usable cutting depth in a single pass, ideal for grooving door and window frames to accommodate weatherseal inserts without needing multiple stepped passes.
• 1/8 in. Cutting Diameter - precisely sized for narrow weatherseal channels and fine detail grooves, including the specific slot profile required for 3 mm (1/8 in.) weatherseal inserts used in energy-efficient door and window retrofits.
• 2-Flute, Right-Hand Rotation - dual cutting edges produce a balanced, smooth cut and efficient chip evacuation, reducing heat buildup and extending the usable life of the bit during repetitive grooving operations.
• 1/4 in. Shank - fits standard 1/4 in. router collets found on handheld routers and router tables, making this bit compatible with a broad range of common routing equipment without adapters.
• Special Double-Sided Design - the bit offers two usable cutting tips in one tool, effectively doubling the value and reducing replacement frequency compared to single-tip alternatives at this diameter.

Why This Product

• If you are retrofitting older doors and windows for improved energy efficiency, this bit is specifically designed to re-groove frames for wind-blocking weatherseal inserts - a task that standard-length straight bits or larger-diameter bits cannot accomplish cleanly.
• The solid carbide construction reaches up to 12 mm in depth without the breakage risk associated with carbide-tipped bits at this narrow 1/8 in. diameter, making it a reliable choice for production or repetitive grooving work.
• The double-sided tip design means you effectively get two cutting surfaces in one bit, reducing per-use cost and extending the time between replacements - a practical advantage for contractors and shop users running this profile regularly.
• At only 1/8 in. in diameter with a long-series profile, this is one of the few routing solutions capable of creating the precise, narrow channels required for 3 mm weatherseal insert profiles without requiring specialty or custom tooling.

Specifications

• Manufacturer Part Number: 812.032.11
• Brand: CMT Orange Tools
• Cutting Diameter: 1/8 in.
• Cutting Height: 1/2 in.
• Total Length: 2 in.
• Shank Diameter: 1/4 in.
• Number of Teeth: 2
• Rotation: Right-Hand (RH)
• Blade Material: Solid Carbide (HWM)
• Series: Long Series

Approved Applications

• Re-grooving door and window frames for weatherseal inserts
• Narrow straight grooves and dadoes
• Fine detail inlay routing
• Deep narrow channel routing where standard-length bits cannot reach
• Energy-efficiency retrofits on existing door and window frames