Shars 13-18 CNC CXA Piston Quick Change Tool Post Set 250-300 New. Please see above pictures, our products are from two different manufactures. They have different type of numbers and logos, they can’t be used by mismatch. Quick Change Tool Post Series. Quick Change Tool Post Type. Set Screw Thread Size. Made of high quality Alloy tool steel 40Gr which is forged and has longer life. Precision ground and hardened. Ta kes only a few seconds to change tools. No time wasted with shims. Tool Post and Tool Holders No. 250-301 Turning Tool Holder, use tool bit 1/2 to 3/4. 250-302 Boring, Turning Tool Holder, use tool bit up to 3/4″ and round shank boring bars up to 3/4″. 250-304 Heavy Duty Boring Bar Holder, can use both 3/4 and 1 shank boring bars. 250-307 Parting Blade Tool Holder, use 3/4 high parting blades. 250-310 Knurling and Turning Tool Holder, use short tool bit 1/2 to 3/4. Piston type tool posts are precision engineered to assure repetitive accuracy. Advanced design provides built in quick tool changing versatility with positive rigidity to meet the most exacting working tolerances. Quickly and easily installed on an engine, bench or turret lathe for a wide range of operations, from fine precise work to heavy duty cutting. Maximum rigidity for chatter free performance. Completely sealed for maintenance free operations. The tool post comes with a blank T-Nut plate, the customer have to do some machining work to make it fit into their own specific lathe T slot. High quality 10.9 grade galvanized screws which have 1 time longer life than others.