
Automatic Back-Chamfering
For back-chamfering or deburring on drill presses, CNC machines, tool or turret lathes, multi-spindle machines and jig boring machines.
Features:
- Consistently accurate back-chamfering, deburring, and back-countersinking operations
- Pilots in hole for precise concentricity
- Rigid support of the cutter virtually eliminates deflection
- Micrometer-stop adjustment
- Standard pilots and cutters for hole sizes from 3/16 to 3/4” (4.75 to 19.05mm)
- Special pilots and cutters available upon request
How Nobur JB Series tools work:

1 | Approach Stroke: The Nobur JB tool is rotating in a machine spindle. The spindle is lowered to bring the tool into position to enter the bore. |
2 | Feed Stroke: The pilot locates in the bore, stopping against the face of the workpiece. As the spindle continues to travel, the tool is compressed so that the cutter feeds out radially into the work. The cutter is rigidly supported in the bore by the pilot to eliminate deflection and ensure concentricity. |
3 | End of Feed Stroke: Radial depth of cut is obtained when the micrometer-stop nut bottoms out. Chamfer location is controlled by rotation of the stop collar, which moves the stop collar extension up or down to position the cutter for accurate chamfer location. |
Standard Tool Specifications

CAPACITY 1 | (A) | (B) | ||
MAX | SHANKS 2 | |||
IN | MM | IN | MM | STRAIGHT |
0.88 | 22.40 | 0.78 | 19.80 | 1/4″ |
3/8″ with tang |
1 Capacity means the suggested maximum chamfer diameter. Dependent upon cutting forces and bore diameter. Stated capacity is for steel.
2 Shank is included with head. Shanks other than shown can be supplied upon request.