I was wondering that myself. What you really need to know is what is the tension on the bolt. On my RF30 clone, it takes about 1/4 turn to go from free to full lock and the thread pitch is .091". Since the poster is also turning about 1/4 turn, the slope of his cam must be similar. For the 50 lb-ft. of torque that I am using, the clamping load is about 4,500 lbs per fastener for a total of 13,500 lbs (per repairengineering.com). Given the short arm and that two bolts are being tensioned, I doubt that the poster is applying that much torque to each bolt.