For sale is Crosby S-209 Screw Pin Shackle which has threads in one side of the shackle allowing the pin to be installed without a nut.  Screw pin shackles are excellent and the shackle of choice when the shackle must be removed repeatedly..  
This shackle shows limited use with most of the paint on the shackle in good condition.  Paint on shackle is original and has not been touched up.   Pin screws easily by hand into shackle as as shown in the picture has full thread engagement when the pin is seated on the shackle.