High tensile strength chromium molybdenum alloy steel body, locking gear, sliding gibs, locking gear head, and locking handle. Thru hardened, ion nitrided, and xylan coated body. Thru hardened and ion nitrided and precision ground locking gear and sliding gibs for wear resistance and repeatability. CNC precision ground and qualified for accuracy and super precise repeatability. Applicable for CNC toolroom lathes, manual toolroom lathes, engine lathes, heavy duty oil-country lathes, super precision high speed applications, tight tolerances and excellent finish requiring applications, deep drilling and boring applications, heavy material removal applications, multi turning, drilling, boring, threading applications. Downward force: rotating the locking gear moves the gib down, expanding the tool post dovetail to lock the toolholder. Outward force: when the gibs make full contact with the toolholder dovetail, the double-angle helix of the locking gear forces the gib outward, neutralizing any backlash to zero. Inward force: the differential between the sliding gib angle and the quick change holder angle pulls the toolholder towards the tool post dovetail surface, creating a one-piece locking effect. The patented locking gear and gibs are made from chromium-molybdenum alloy steel. The core thru hardness is 40-44 Rc and the surface is Ion-Nitrided to a hardeness 60-64Rc to ensure a long working life and rust resistance under harsh working conditions. An anti-rotation system is built into the tool post with antirotation pins, which are engaged with a "T" Nut or compound to provide maximum rigidity and stability when performing drilling, boring and heavy roughing operations.