Front Wheel Hub (5/8" ID Bearings) Includes Hardware. Billet aluminum hubs with the American bolt pattern Wheel hubs come complete with 1/4-28" hardware and high speed 5/8” bearings. For go kart, bar stool, midget racing. Wheel hubs come complete with 1/4” hardware and are drilled and tapped for both 1/4” & 5/16” bolts. These hubs are made of aluminum and have an approximate outer diameter of 3". 3 bolt pattern on a 2-1/2" bolt circle Shoulder diameter- 1-3/4" Hubs are 1.80" wide