The Accu-Bore from AB Tools, Inc. is a Solid Carbide boring tool (Micrograin Heads silver soldered on Solid Carbide Shanks). They can be set to any bore depth with maximum rigidity. Very simple design for a boring bar with a carbide tip brazed on a solid carbide shank then ground to cut. The length of the projection of these tools and the depths they can bore can easily be adjusted due to the straight shanks. Proudly made in the USA by AB Tools, Inc.