CMT Mortising Chisel and Bit - 3/8" Diameter, 3/4" Shank, Right Hand by CMT is a high-speed steel chisel and bit set designed for cutting clean, square mortise holes in solid wood. Built for use on any standard drill press mortising attachment or dedicated mortising machine, this tool makes traditional mortise-and-tenon joinery more accurate and efficient. Whether you are crafting furniture, constructing door and window frames, or joining structural wood components, having a precisely manufactured mortising chisel and bit set is essential to achieving tight-fitting, strong joints that stand the test of time.

Key Features

• 3/8" Cutting Diameter - produces a precisely sized square mortise hole to match standard 3/8" tenon dimensions, reducing the need for secondary fitting or trimming.
• HSS (High-Speed Steel) Construction - delivers superior edge retention and heat resistance compared to standard carbon steel, meaning the chisel stays sharper longer during extended mortising sessions in both hardwood and softwood.
• 3/4" Shank Diameter - fits the standard 3/4" chuck found on most drill press mortising attachments and benchtop or floor-standing mortising machines, making setup straightforward without adapters.
• Right-Hand (RH) Rotation - compatible with conventional right-hand-rotation drill presses and mortising machines, ensuring safe, correct operation with standard equipment.
• Single-Tooth Bit Design - the 1-tooth bit works in combination with the surrounding chisel to clear waste material efficiently and produce clean-walled square holes in one pass, reducing tear-out.
• Universal Mortising Machine Compatibility - works with any standard drill press mortising attachment or dedicated mortising machine, giving woodworkers the flexibility to use the tools they already own.

Why This Product

• The mortise-and-tenon joint remains one of the strongest and most accurate joinery methods in woodworking - this chisel and bit set is purpose-built to execute that joint cleanly, making it the right choice for furniture makers and finish carpenters who refuse to compromise on joint quality.
• HSS material means the cutting edge holds up through tough hardwood species without dulling quickly, reducing downtime for sharpening and keeping your workflow moving on production or multi-piece projects.
• The 3/4" shank is the industry-standard size for mortising attachments, so this set integrates directly into most existing drill press setups without requiring special adapters or additional hardware.
• At 3/8" diameter, this set covers one of the most commonly used mortise sizes in door frame, window frame, and furniture construction - making it a practical, everyday tool rather than a specialty item.

Specifications

• Manufacturer Part Number: 543.095.51
• Brand: CMT Orange Tools
• Diameter: 3/8"
• Shank: 3/4"
• Rotation: RH (Right Hand)
• Material: HSS (High-Speed Steel)
• Number of Teeth: 1

Approved Applications

• Drill press with mortising attachment
• Benchtop mortising machine
• Floor-standing mortising machine
• Cutting square mortise holes in solid hardwood
• Cutting square mortise holes in softwood
• Traditional mortise-and-tenon joinery
• Furniture making and cabinet construction
• Door and window frame construction

Frequently Asked Questions

What machines is this CMT mortising chisel and bit compatible with?

This set is compatible with any standard drill press mortising attachment as well as dedicated benchtop and floor-standing mortising machines. The 3/4" shank fits the standard chuck size found on most of these machines, so no special adapters are typically needed.

Why is HSS material important for a mortising chisel and bit?

HSS (High-Speed Steel) retains its cutting edge at higher temperatures than standard carbon steel. This means the chisel and bit stay sharp longer when working through dense hardwoods or during repeated mortise cuts, resulting in cleaner walls and fewer interruptions to sharpen or replace tooling.

What size mortises does the CMT 543.095.51 produce?

This set produces 3/8" square mortise holes. The 3/8" diameter is one of the most commonly used mortise sizes in furniture making, door construction, and window frame joinery, making this a versatile choice for a wide range of woodworking projects.

Is this chisel and bit set designed for right-hand or left-hand rotation machines?

This set is designed for right-hand (RH) rotation, which is the standard direction of rotation for conventional drill presses and most mortising machines. Always confirm your machine's rotation direction before installing any mortising chisel and bit set.