Description: Made of high quality Alloy tool steel 40Gr which is forged and has longer life, not Aluminum. Takes only a few seconds to change tools. High quality 10.9 grade galvanized screws which have 1 time longer life than others. 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. Tool Post Set 13-18" CXA ...