Kraft Tool Co.® CF304 6" x 4.5" Bronze Big Bit Groover with Wooden Handle. This unique, longest wearing one-piece casting won't wear out with extended use in concrete like steel groovers. Each blade is hand polished for a clean, smooth professional finish every time. This 6" x 4-1/2" groover features a deep bit that has a 3/8" radius and is 3/4" deep, 7/8" wide. A durable tool for creating control joints in sidewalks, driveways, and other surfaces. The 4-1/2" smooth wood provides a comfortable grip. The handle is secured directly to the casting.