Our 17-4 Shafts are precision machined with a standard propeller shaft taper, milled for 1/4" key and threaded with 3/4" standard thread on 1" and 1-1/8" shafts. Standard sizes are listed, or as a special service, we will cut to your specified length. Please allow approximately one week for this service. Overall length can be determined by measuring from the coupling in the boat to the aft end of the strut, and adding 5" for 1" shaft.