One set of twelve (12) replacement tines for some Howard E, HR, HX, 15-20-30-35, HB-ST180, 500S, 500B series rotocultivators which includes six (6) 63592 and six (6) 63593 tine. These tines have two 1/2" mounting holes 2-1/4"" on center, are 1/4" thick and are 3-1/8""wide. If you need more tines just increase the quantity to purchase at checkout. We sell many replacement parts for the Howard rotocultivators. 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 our store often. Part Numbers: 63592 / 63593, 3900 / 3901, 9930 / 9931