Dimensions vary or are out of tolerance

?Likely causes

• Cutting force deflects the tool or workpieceAgreed by 2+ makers^{[1][2][3][4][5]}
• Poor insert accuracy class (M class) or poor clampingAgreed by 2+ makers^[1][2][6][4]
• Tool wear progresses and dimensions change graduallyAgreed by 2+ makers^[7][8][2]
• Large tool runout or overhangAgreed by 2+ makers^[4][8]
• Large cutting heat degrades accuracyOne maker^[2]

✓Fixes

Cutting conditions

• Reduce the depth of cut and feed for finishing (reduce the finishing allowance)Agreed by 2+ makers^[4][8][9][3]
• If wear is throwing off dimensions, reduce the cutting speed and increase the feedOne maker^[2]

Tool

• Use a high-precision insert (M class to G class)Agreed by 2+ makers^[1][2][6]
• Reduce cutting force with a sharp edge geometry (large rake angle, small corner radius, small honing)Agreed by 2+ makers^[1][2][6]
• Use a grade with high wear resistanceOne maker^[2][6]
• Use a rigid tool (carbide, thick shank, short cutting length)Agreed by 2+ makers^[4][9]

Setup

• Increase mounting rigidity, shorten the overhang, and reduce machine playAgreed by 2+ makers^{[1][2][4][8][6]}
• Reduce tool runout (retighten or replace the holder)Agreed by 2+ makers^[4][8]

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