Micro 100 Boring Bar, manufacturer part number PBT4-260500.
Specifications: Minimum Bore Diameter: 0.2800 in; Maximum Bore Depth: 1/2 in (0.5000 in); Shank Diameter: 5/16 in (0.3125 in); Overall Length: 2-1/2 in (2.5000 in); Hand Direction: Right; Neck Diameter: 0.2150 in; Centerline Offset: 0.1038 in; Projection: 0.0450 in; Corner Radius: 0.0040 in.
Coating/Finish: Uncoated. Unit of measure: Inch.