while part proving time bore over size by 0.04|previous part bore not finish so change the insert and different supplier insert so |customer recommended parameter not accurate on this type of operation   |This high RPM S1200 Is grater than vc so bore over size |Why1-In first part surface Finish inside Bore was not acheived. 
Why2-Bore finish done with RPM of 1200.
Why3-Insert changed for the next part which resulted in Bore oversize.
