Micro 100 Boring Bar, manufacturer part number QBT4-260500.
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: 2.0000 in; Hand Direction: Right; Neck Diameter: 0.2150 in; Centerline Offset: 0.1038 in; Projection: 0.0450 in; Length from Holder: 0.8530 in; Corner Radius: 0.0040 in.
Coating/Finish: Uncoated. Unit of measure: Inch.