1/4-20 x 2-1/4" Hex Head Bolt. Used In MSS12 and MSS12R Pulley assemblies. Use Nut #32019 Nylon Insert Locking Nut. Also found in the pre-assembled #926208 MSS12 Complete Pulley Assembly.
Also used in the MPS Ground Socket - as the bottom stop - and can be found in the #900003 MPS Ground Socket Hardware.