391-1425-017 is a Grade 8 stud measuring 5/8-11 x 12-1/2 inches. Grade 8 hardware is built for high-stress, high-torque applications where a standard fastener would fall short, making this stud suited to heavy-duty mounting and clamping jobs. It threads to a 5/8-11 UNC spec, a common thread pitch for hydraulic pump and motor mounting hardware.Interchanges:WA20-51-0324FeaturesGrade 8 stud construction5/8-11 UNC thread12-1/2 inch overall lengthTech SpecsThread: 5/8-11 UNCLength: 12-1/2 in.Grade: 8