CMT Roundover Bit with Insert Knives - 1/2" Cutting Diameter, 1/8" Radius, 1/4" Shank is a precision edge-forming router bit engineered for clean, consistent roundovers on hardwood, softwood, laminates, and chipboard. Designed by CMT for use in handheld routers and router tables with a 1/4" collet, this bit delivers smooth, repeatable edge profiles with the efficiency of dual-sided replaceable insert knives fixed by special Torx screws. Whether you are rounding over cabinet edges, laminate panels, or decorative trim, this bit provides reliable performance and long-term value through its interchangeable knife system.

Key Features

• Two replaceable insert knives with 2-sided profiles - each knife blade is profiled on 2 sides, so when one cutting edge dulls you can flip or replace it, reducing downtime and extending the working life of the bit without buying a whole new tool.
• Torx screw knife retention system - special Torx screws lock each insert knife securely in place, ensuring the blades stay fixed during operation and reducing the risk of vibration-induced movement for cleaner cuts.
• Ball bearing guide - the integrated ball bearing follower rides along the workpiece edge to maintain a consistent 1/8" radius profile without the need for fences or jigs, making it ideal for freehand router work and edge finishing.
• 1/8" cutting radius on a 1/2" diameter profile - this compact roundover geometry is well suited for softening edges on laminate panels and light decorative edgework where a subtle, refined profile is preferred.
• Hardwood (HW) knife material - the insert knives are manufactured from hardwood-grade material suitable for cutting hardwood, softwood, laminates, and chipboard, supporting a wide range of woodworking applications.
• Right-hand rotation - the standard right-hand rotation is compatible with the vast majority of handheld routers and router tables, requiring no special setup or adapters.
• 1/4" shank diameter - fits routers equipped with a 1/4" collet, making this bit accessible for compact and mid-size router models commonly used in shops and on job sites.
• 2-flute cutting geometry - the 2-tooth configuration provides balanced cutting with each pass, helping to reduce heat buildup and produce a smoother finished edge on laminates and wood composites.

Why This Product

• The 2-sided replaceable insert knife design means you get multiple fresh cutting edges per knife set - an efficient solution for production work or frequent use on laminate materials where edge sharpness directly impacts finish quality.
• The ball bearing guide eliminates the guesswork of freehand routing by keeping the 1/8" roundover profile consistent along any straight or curved edge, which is especially valuable when finishing laminate panels or cabinet components.
• At a 1/8" radius with a 1/4" shank, this bit occupies a versatile middle ground - compact enough for detail work and decorative edging, yet capable of handling the demands of laminate and hardwood edge profiles in a router table setup.
• The Torx screw knife-locking system adds a layer of operational confidence, keeping blades firmly seated during cutting so you spend less time checking setup and more time producing consistent, professional-quality roundovers.

Specifications

• Manufacturer Part Number: 661.031.41
• Brand: CMT Orange Tools
• Cutting Diameter: 1/2"
• Overall Diameter: 1-1/16"
• Small Diameter: 12.7mm
• Radius: 1/8"
• Cutting Height: 1/8"
• Total Length: 2-17/64"
• Shank Diameter: 1/4"
• Number of Teeth: 2
• Knife Material: HW
• Rotation: Right-Hand

Approved Applications

• Roundover edge profiling
• Edge finishing on laminates
• Decorative edgework on hardwood and softwood
• Edge softening on chipboard and plywood panels