New Products  enlarge  enlarge   Disc Racks Fast Adjusting Collars for Square Splines Our fast adjusting collars are made for double square splines too. Using a 1/2" nut driver to tighten and loosen only one nut, the disc will adjust with little or no resistence. Pictured is our Quick Collar #QC500S on a double 1/2" square spline. Also available for double 3/8" square splines.  enlarge  enlarge   Disc Racks Quick Adjust Disc Rack Our new quick adjust collar device can replace the old block collar design. Features improved contact with the spline. No more worries about the set screw seizing in the collar. If the nut and bolt do seize, you can simply remove and replace with new fasteners. The collar is still good. Uses the same mounting holes in your discs. One bolt adjustment uses 1/2" standard nut driver. It's also less expensive than the block collar. these pictures show part # QD750R to fit the 3/4" round spline. We also make similar collar devices for double 3/8" and double 1/2" square splines