Dear Home Depot Customer: We are sorry to hear that you had trouble with this blade. RIDGID 4" Continuous Diamond Blade comes with 7/8 in. arbor, also comes with 5/8 in. and 20 mm adapters. The adapter ring is meant to pop in or out to accommodate the arbor size of your saw. When installing, please make sure the blade sits flush to the backing flange of your tool. It is necessary to ensure a proper fitting before securing the blade with screw nut/flange of your tool. We would like to discuss the situation and get better details of what you encountered and assist you with a solution. Please feel free to give us a call at our RIDGID customer support number at (877) 224-2969 so that we can help.