Thats what I tried but i get .6625in or 16.83mm. I am able to thread a 5/8-18 bolt into the eye fairly nice, but 5/8-18 nut will not thread onto the ram. And the thread pitch sure seems to be m1.5 although the 18 does fit well with minimal slop. Maybe it's a 17mm? Nowhere near me with that...
