
Why 1. Dim 28 found dig Mark
Why 2. during machining Ø12xR2 Bull cutter broken
Why 3. New Tool trail under process 
Why 4. old tool life is 15Nos |Why 1. dim 26mm surface dig mark found during Ø8.1H7 hole machining
Why 2. Ø5 endmill found blunt  
Why 3. Replace the blunt end mill with new Ø5 End mill 
Why 4. during the replacing the new end mill wrong work offset used|Why 1. Ø18.8 E7 bore oversize by 0.16
Why 2. during boring insert found Blunt  
Why 3. Replace the blunt insert with new one 
Why 4. during the replacing the new insert wrong insert used
Why 5. R0.2 insert used insted of R0.4 |Why 1. Ø18.8 E7 bore oversize
Why 2. During U-drill Process machine spindle overload 
Why 3. found U-drill broken ( U-drill life only for 3 nos) |
Why 1. dim 51 thickness undersize
Why 2. during machining Ø16 cutter ,insert loosen
Why 3. found M2.5 screw loose
Why 4. holder insert sitting area worn out and damage

Why 1. Ø18.8 E7 bore rough & unclear at one end
Why 2. During U-drill process one insert fly away 
Why 3. Found insert screw broken
Why 4. hope screw loosen