This set came with a metric thread on the 3MT boring head shank and head. If you never plan to swap the head to another shank, it’s not an issue.
The carbide tipped 9-piece boring bar set includes three different length boring bars each for minimum bores of 5/16″, 7/16″, and 9/16″. The bore depth ranges from 3/4″ to 3″. The heat treated, alloy steel shanks are held to 0.000 to -0.0005″ from the nominal diameter.The drawbar thread is 3/8″-16.Note: If you have a Grizzly G8689 or Micro-Mark 82573 mini mills with the 3 Morse taper spindle, that has a metric threaded drawbar, you will need our 3/8″-16 threaded drawbar P/N 1637 to use this boring head.
