3 machinist boring bar bit holders for 5/16”sq bits

3 machinist boring bar bit holders for 5/16”sq bits

Three machinist boring bar bit holders - each is about 15/16“ diameter for mounting on ¾“ threaded end of a bar. Two of the holders secure the bits via an internal “plug“ in the threaded end that squeezes the bit when the holder is tightened onto the bar (plug is square on the bar end, and has a 45° surface on the bit end). The bits are held at about a 45° angle to the bar. The third holder holds the bits at a 90° angle to the bar, with the end of the bar directly squeezing the bit in place.