CMT Mortising Chisel and Bit - 5/8" Diameter, 3/4" Shank, Right-Hand Rotation is a precision HSS (High-Speed Steel) chisel and bit set designed for cutting clean, accurate square mortise holes in wood. Built for use with any standard drill press mortising attachment or dedicated mortising machine, this set makes traditional mortise-and-tenon joinery more accessible and consistent - delivering the tight, strong joints that woodworkers have relied on for centuries. Whether you are building furniture, constructing door frames, or working on window casings, the CMT mortising chisel and bit combination gives you the right tool for the job.

Key Features

• HSS (High-Speed Steel) Construction - High-speed steel provides excellent hardness and edge retention, allowing the chisel and bit to cut through solid hardwood and softwood cleanly without rapid dulling, reducing the need for frequent resharpening.
• 5/8" Cutting Diameter - Produces a 5/8" square mortise hole in a single pass, matching standard tenon sizes commonly used in furniture making and door and window frame construction for reliable, repeatable joints.
• 3/4" Shank - The 3/4" shank is sized to fit most standard drill press mortising attachments and dedicated mortising machines, making this set easy to mount and use without adapters or special tooling.
• Right-Hand (RH) Rotation - Designed for standard right-hand rotation, compatible with the direction of travel on conventional drill presses and mortising machines, so setup is straightforward and safe.
• Matched Chisel and Bit Set - The chisel surrounds the drill bit so both components work together simultaneously - the bit bores out the waste material while the chisel squares the walls, producing a clean mortise in one operation rather than requiring multiple separate steps.

Why This Product

• Purpose-Built for Mortise-and-Tenon Joinery - The mortise-and-tenon is one of the strongest and most accurate wood joints available. This chisel and bit set gives woodworkers a dedicated, efficient way to cut the mortise half of that joint with consistency across multiple pieces.
• Broad Machine Compatibility - Because the 3/4" shank fits any standard drill press mortising attachment or mortising machine, this set works with equipment you likely already own - no specialized or proprietary tooling required.
• HSS Material for Long-Lasting Performance - High-speed steel maintains its cutting edge longer than standard carbon steel alternatives, meaning less downtime for sharpening during extended woodworking sessions and more consistent hole quality throughout a project.
• One-Pass Square Hole Cutting - The integrated chisel and bit design cuts a clean-walled, square mortise in a single plunge, saving time compared to methods that require multiple tool changes or passes to achieve a square opening.

Specifications

• Manufacturer Part Number: 543.158.51
• Brand: CMT Orange Tools
• Description: Mortising Chisel and Bit D=5/8" S=3/4" RH
• Diameter: 5/8"
• Shank: 3/4"
• Rotation: RH (Right-Hand)
• Material: HSS (High-Speed Steel)
• Number of Teeth: 1

Approved Applications

• Cutting square mortise holes on drill press mortising attachments
• Use with dedicated benchtop and floor-standing mortising machines
• Traditional mortise-and-tenon joinery
• Furniture making and cabinet construction
• Door frame and window frame construction
• Solid hardwood and softwood workpieces