This heavy-duty HSS bridge reamer kit is constructed from M2 HSS to sharp and fast execution in most strong steels. The tapered point design allows the reamer bit to enter non-linear, overlapping holes to align bolt holes. Enlarge the holes in the steering knuckle and linkage arms. Designed to align existing holes and enlarge undersized holes. This taper chuck reamer kit increases the taper for easier drilling, especially for drilling larger holes in connecting rod arms and steering knuckles. [Application]: Commonly used in bridge, construction, steel structure /fabrication, automotive (truck and trailer) industries. Designed for use in stainless steel, aluminum, copper, alloys, plastics. [Size]: 1 set of 4 pieces, including 3/8inch (fits 3/8inch shank chuck), 1/2inch, 5/8inch and 3/4inch (fits 1/2inch shank chuck) Please note:There is a slight color difference or difference in kind, it does not affect the use, please do not mind, thank you! Colour:Black Material:high speed steel Package Contents: 4 * Drill Bridge