CMT Keyhole Router Bit - 3/8" x 7/16" with 1/2" Shank by CMT is a precision-engineered keyhole slot cutter designed to create secure wall-mounting slots for picture frames, plaques, mirrors, and other wall hangings. Using a plunge router or router table, this single-tooth carbide-tipped bit cuts a T-shaped keyhole profile that allows a screw or nail head to lock in place, keeping wall hangings flush, straight, and firmly attached. Whether you are a woodworker mounting decorative panels or a finish carpenter hanging shelving and signage, this keyhole routing bit delivers the clean, consistent slot geometry needed for professional results.

Key Features

• Keyhole Slot Profile - cuts a T-shaped hanging slot that locks onto screw or nail heads, keeping frames, plaques, and wall hangings perfectly straight and securely attached to the wall without visible hardware.
• Single Tooth (1 Flute) Carbide Tip - the 1-flute HW (hardmetal carbide) cutting edge provides clean entry and smooth slot walls on wood, plywood, MDF, and composite materials, reducing tearout in finished workpieces.
• 3/8" Large Diameter x 7/16" Cutting Height - these precise slot dimensions accommodate standard screw and nail heads, ensuring a snug, rattle-free fit for wall-mounted objects.
• 4.76 mm Small Diameter Neck - the narrow neck diameter allows the shank of a fastener to pass through cleanly while the wider head locks behind the shoulder of the slot, creating a reliable mechanical hold.
• 1/2" Shank - the full 1/2" shank provides maximum stability and reduced vibration in both plunge routers and router tables, contributing to straighter, more accurate keyhole cuts.
• 2 1/8" Total Length - the overall length gives adequate clearance above the workpiece surface when used with a plunge router, allowing smooth plunge entry into the material.
• Right-Hand (RH) Rotation - compatible with all standard router spindles, ensuring correct cutting direction without any setup modifications.
• CMT Orange Shield Non-Stick Coating - prevents the bit from overheating, reduces pitch and resin buildup on the cutting surfaces, protects against corrosion, and extends tool life - keeping the bit performing cleanly over many repeated cuts.
• SinterHIP Industrial Chrome Carbide - the carbide is processed via Hot Isostatic Pressing (HIP), which prevents material failure under stress and extends cutting life compared to conventionally sintered carbide.
• Tri-Metal Brazing (Silver-Copper-Silver) - a three-layer braze bond secures the carbide tip to the body, protecting the joint when cutting harder wood or composites and reducing the chance of failed welds that could cause tip separation.
• Anti-Kickback Design - controls depth of cut and minimizes kickback, improving operator safety especially during plunge entry on a handheld router.

Why This Product

• For anyone regularly mounting frames, plaques, or wall hangings, the keyhole slot this bit creates eliminates the need for visible brackets or picture-hanging hardware - the mounting screw stays hidden behind the workpiece for a clean, professional appearance.
• The CMT Orange Shield non-stick coating and SinterHIP carbide work together to maintain sharp, clean cutting edges longer - meaning fewer sharpening cycles and more consistent slot quality across production runs or repeated hobby projects.
• The 1/2" shank paired with the anti-kickback design makes this bit a stable, controlled choice for use with a plunge router - the recommended setup for keyhole slot cutting - reducing the risk of the workpiece shifting or the bit deflecting mid-cut.
• The Tri-Metal Silver-Copper-Silver brazing provides a stronger carbide-to-body bond than single-metal brazes, making this bit a reliable choice when working with harder hardwoods or composite panels where tip stress is elevated.

Specifications

• Manufacturer Part Number: 850.501.11
• Brand: CMT Orange Tools
• Product Type: Keyhole Bit
• Diameter: 3/8"
• Small Diameter: 4.76 mm
• Cutting Height: 7/16"
• Total Length: 2 1/8"
• Shank: 1/2"
• Number of Teeth: 1
• Blade Material: HW (Hardmetal Carbide-Tipped)
• Rotation: Right-Hand (RH)
• Country of Origin: Made in Italy

Approved Applications

• Routing keyhole slots for wall-mounted picture frames and mirrors
• Creating hanging slots for plaques, signs, and decorative panels
• Wall mounting slots on shelves and cabinetry components
• T-slot routing for removable wall-mounting joints
• Keyhole slot cutting in solid hardwood, softwood, plywood, MDF, chipboard, and laminates