Heavy Duty set of three (3) replacement aftermarket Copperhead blades that are 0.240" thick (instead of standard 0.204") to ensure longer blade life and fit 36" Cut Gravely Mowers that have 5/8" round blade mounting, 2 for 36" cut . These blades are 18" long by 2-1/2" wide with a 5/8" center hole and .240" thick. Blade specifications as follows: Overall Length: 18" Width: 2-1/2" Thickness: 0.240 Mounting Hole: 5/8 Round If you are not sure if these will fit your mower just send me an email with your model number and I will be happy to confirm them for you! One day handling and free shipping! We have more lawn and garden items available than we have time to list them. If you don't see the parts you need listed please contact us we would love to earn your business. We are listing new items frequently so please check back often. Replaces part numbers: GDU10231 We stock a wide variety of replacement parts for most Lawn and Garden and Agricultural Equipment please contact us if you have any questions or if you would like more information. Your satisfaction is important to me, if you have any questions, concerns or comments please let me know, I will do everything I can to answer your questions, correct your problem and help you out.!