The three most common bolt and nut sizes are combined with the classic park tool 3 way ldquoyrdquo body 8mm 9mm and 10mm forged cr v steel sockets park tool st 3 3 way socket wrench features the three most common bolt and nut sizes are combined with the classic park tool 3 way y body 8 mm 9 mm and 10 mm forged cr v steel sockets covered by park tool39s legendary limited lifetime warranty