Micro 100 Boring Bar, manufacturer part number BB6-260700G.
Specifications: Minimum Bore Diameter: 0.2800 in; Maximum Bore Depth: 0.7000 in; Shank Diameter: 5/16 in (0.3125 in); Overall Length: 2-1/2 in (2.5000 in); Hand Direction: Right; Neck Diameter: 0.1950 in; Centerline Offset: 0.1038 in; Projection: 0.0650 in; Corner Radius: 0.0060 in.
Coating/Finish: TiN. Unit of measure: Inch.