The thru-tubing underreamer is designed to pass through borehole restrictions and hydraulically open to a preset diameter. It has proved effective in removing cement, scale, and hard debris from the liner below the production string. This underreamer can also be configured as an anchor for pipe-cutting applications. Blades and pilot mills are available with carbide dressing, diamond dressing, and carbide inserts to maximize performance in any application. The thru-tubing underreamer features