Material?Diamond Cutting Diameter?4-1/4 inches shank Type?Threaded Brand??KELINER The diamond core drill bit adopts the design of an industry-standard 1-1/4”-7 threaded connection. It is compatible with both handheld core drills and professional drilling rigs, and serves as a multi-functional tool for contractors and builders. 4" Diamond Core Drill Bit is built to tackle the tough materials with ease, whether it's concrete, brick, stone, or masonry. Crafted with precision and designed for durability, this diamond core drill bit is a for professionals and DIY enthusiasts.It’s ideal for installation projects such as HVAC systems, range hoods, and stair railings, as well as larger infrastructure tasks like roadways and airports.