This is just one of hundreds of surplus boring bars from a technical school. These were originally made for Chipblaster, the manufacturer of high pressure coolant systems, to demonstrate their product.
Nearly everyone is new, all are U.S.A. made.
This item is:
Bar type: A24-STUPR3-HP
Steel with coolant hole.
1 1/2 inch diameter.
Screw held insert.
Offset shank with negative 3 degree end or side cutting edge angle.
Insert size: .375
SORRY, NO HARDWARE CAME WITH THESE!