Thread produced is too large

Thread produced is too large
Possible causes Solution
incorrect tap, tap geometry not suitable or the application apply correct tap for the material to be machined
tapping size hole too small observe tapping size hole table in the technical section. Note different tapping size hole diameters for fluteless taps.
alignment error of tapping size hole or position - check for correct tool clamping
- apply floating tap holder
- check core drill
machine spindle axially restricted - use mechanical feed
- apply tension/compression tap chuck
cold welding at the flank of the tap - apply new tap
- apply coated tap
- optimise lubrication
lead of tap unsatisfactory due to insufficient thread depth - tap with forced feed
- apply tap with modified lead
cutting speed too high - reduce cutting speed
- improve lubrication
lubrication or coolant supply insufficient ensure sufficient and suitable coolant supply and check concentration
tolerance specification on tap does not correspond to specifications on drawing and/or thread gauge apply correct tap for required tolerances