Threaded Bung With Jam Nut 1 1/2 Inch-12 RH Thread Set RockJock 4x4RockJock's Threaded Bung and Jam Nut Sets have been a staple in our Johnny Joint product line since its inception in 1996! These bungs are used in many applications where a custom vehicle builder has the facilities to fabricate his own arms. All of our bungs are CNC machined from premium steel hex stock, in house, on our own machines. Hex size is kept to a minimum and a matching small hex jam nut (as opposed to the large hex of commonly available jam