For sale are 27 pcs of a USA MADE! (NOT in Taiwan, or who knows where) , Cat 40 pull studs/retention knobs, new, but old stock, you get 27 pcs. As pictured, the distance from the threaded end flange to the largest dia end of the 45 degree is about 1.0". The neck is about .393" diameter, the large flange dia is about .935" dia, the knob dia is about .588" dia. and these are all coolant through (.197" dia hole). These are made in one of the best small machine shops in the entire world-Us, at A & T Machining Co, in Ann Arbor, MI, and were carbo-nitrided by one of the very best heat treat companies in the entire Detroit area , Detroit Steel Treating. These are 1215 steel, CASE HARDENED TO A MIN OF .025" DEEP! These are super strong and super hard! And, then we had them black oxided to prevent rust.
in 2017, we made 200 of these, we used about 100 of them as we had a 2017 Haas VF6 machining center. We just now in April of 2025 have sold our Haas, and we only have Mazaks now, and we do not need these style pull studs anymore. Anyhow, we used these retention knobs for 8 years with absolutely NO problems, the .750" wrench flats did not even get rounded off at all on any of the 100 or so that we used over 8 years.
The overall length is about 2.305", 5/8-11 threads. These also have the .640 step diameter up above the thread undercut that goes into the cat 40 holder to maintain concentricity, as our machine was a high speed spindle at 15K RPM, so the holders would not shake and vibrate if the retention knob spun off center..