... of dia.300mm ,still can be used well after re-mill blade 2times and adjust length 4times(total 4. ... of dia.300mm ,still can be used well after re-mill blade 3times and adjust length 4times(total 5. ... dia.300mm ,will be changed 3 drive links after re-mill blade 5times and adjust length 5times(total 6.7mm ... dia.300mm ,will be changed 4 drive links after re-mill blade 4times and adjust length 4times(total 7. ...