1. Tap breakage
Common causes:
● The bottom hole diameter is too small, and the chip removal is poor, causing chip blockage
● When tapping a blind hole, the drilling depth is not enough
● The tapping speed is too high or too fast
● The tap used is not coaxial with the bottom hole diameter
● The tap grinding parameters are not suitable
● The hardness of the workpiece is unstable
● The tap has been used for too long and is excessively worn
Solutions:
● Correctly select a drill bit that matches the tap size for drilling
● The depth of the bottom hole must meet the specified standard
● Appropriately reduce the cutting speed and select according to the standard
● Correct the thread when tapping the tap thread Taper and bottom hole, ensure that their coaxiality meets the requirements, and use floating tap chuck
●Increase the tap rake angle and shorten the cutting tap length
●Ensure that the workpiece hardness meets the requirements and use a safety chuck
●If the tap is found to be worn, it should be replaced in time to avoid breaking in the hole and causing additional losses
2. Tap tooth breakage
Common causes:
●The tap rake angle is too large
●The cutting thickness of each tooth of the tap is too large
●The quenching hardness of the tap is too high
Solution:
●Appropriately reduce the tap rake angle
●Appropriately increase the length of the cutting tap
●Reduce the hardness and replace the tap in time
3. Taps wear too fast
Common causes:
● Too high speed when tapping tap threads, improper selection of tap grinding parameters, improper selection or insufficient use of cutting fluid
● Too high hardness of the workpiece material, burning when the tap is sharpened
● Too large tap thread middle diameter, improper selection of middle diameter accuracy grade
● Burrs generated when sharpening the tap
● Too short length of the tap cutting cone
Solutions:
● Appropriately reduce the cutting speed, reduce the tap rake angle, and lengthen the cutting cone; select a cutting fluid with good lubricity, and perform appropriate heat treatment on the workpiece being processed
● Select a tap middle diameter with an appropriate accuracy grade, eliminate burrs generated by the tap, and appropriately increase the length of the cutting cone