Rough, torn, or fuzzy finished surface

?Likely causes

• Built-up edge or welded material is on the cutting edgeAgreed by 2+ makers^{[1][2][3][4][5]}
• Chatter vibration is occurringAgreed by 2+ makers^{[1][2][3][6][5]}
• Feed is large relative to the corner radius or wiper flat width (feed marks)Agreed by 2+ makers^{[7][1][4][8][9]}
• Tool wear or chipping is advancedAgreed by 2+ makers^{[2][4][9][10]}
• Chips hit the machined surface or are being recutAgreed by 2+ makers^{[7][9][11][10]}
• Runout of the tool or spindle, or uneven insert heightsAgreed by 2+ makers^{[1][4][11][9][6]}
• Cutting speed is low (e.g. fuzzy surface on mild steel)Agreed by 2+ makers^[9][2][3]
• Large boundary wear makes the machined surface fuzzyOne maker^[7]

✓Fixes

Cutting conditions

• Increase the cutting speed to prevent built-up edge and weldingAgreed by 2+ makers^{[1][2][3][4][9][5]}
• Reduce the feed (in face milling, keep the feed per revolution within the wiper flat width)Agreed by 2+ makers^{[7][1][4][8][9][11]}

Tool

• Use a wiper insert or a larger corner radiusAgreed by 2+ makers^{[7][1][4][6][3]}
• Use a sharp positive geometry with a large rake angle and small honingAgreed by 2+ makers^[1][2][3]
• Use a grade with low affinity to the workpiece material (cermet or coated)Agreed by 2+ makers^{[7][1][2][4][3]}
• Replace worn or chipped cutting edges earlyAgreed by 2+ makers^[4][9]

Setup

• Reduce runout (align insert heights, and check spindle and holder runout)Agreed by 2+ makers^{[1][4][9][11][6]}
• Direct chips away from the machined surface (select a chip breaker, use air blow)Agreed by 2+ makers^{[7][9][11][10]}

Coolant

• Use wet cutting, or a highly lubricating fluid such as non-water-soluble oil, to suppress weldingAgreed by 2+ makers^[2][3][5][9]

▦Notes by material

• Mild steel (low-carbon steel): Prone to fuzzy surfaces. Welding-resistant grades, higher cutting speed, and non-water-soluble oil are listed as countermeasures^[2][3][12]
• Pure aluminum and copper: Soft and ductile, so welding tends to roughen the finished surface^[13]

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