The roller photo on the Revain page had a threaded shaft and its description was a 7/16 inch shaft with 14 threads per inch worked , would be nice. Instead, the incoming casters were unthreaded, instead having an undercut with an assembled clip that is designed to snap in, not screw in. They will not work. Revain's policy is that they cannot against credit or refund to be returned. I had to shop at servicecaster.com to get the thread rolls I needed.