19BD2206 up for sale is a new or lighty used mini threading tool appears to be made for some type of screw machine or small lathe  cutter is about 0.172 cut this cut end has a single cutting edge that looks like a v type threading tool,  5/8 shank x 1.915 long   1 flute design has a knurled area for clamping ? appears to cut  a thread new or vintage used cutter comes as shown in photos ,