A front-loaded, side-activated modular drill includes a shank and a replaceable cutting insert installed on and engaging the tool shank. The shank has a pocket for supporting the cutting insert when the cutting insert is installed within the pocket. The pocket includes a first centering wall having an aperture with internal threads formed with a first pitch and a second centering wall having an aperture with a first portion with internal threads formed with a second, different pitch. A first member is threaded into the aperture of the first centering wall, and a second member is threaded into the second centering wall. The first member is threaded into the second member. The cutting insert has an opening in a trailing end for allowing the first member to pass therethrough. Rotation of the first member causes the centering walls to elastically deform and move relative to each other.