Troubleshooting for thread milling

• The part of the cutting edge which is not in cut is damaged by chip hammering, leading to poor surface and excessive flank wear

• Increase cutting speed
• Reduce feed at the beginning of the cut
• Improve stability
• Increase number of passes
• Use a full-profile insert

Poor surface finish and cutting edge frittering when the built-up edge is torn away.

• Cutting zone temperature is too low
• Very sticky material, such as low-carbon steel, stainless steels and aluminium

• Increase cutting speed or feed
• Use oil mist or cutting fluid

• Excessive wear causing a weakened edge
• Cutting edge breakthrough on the trailing edge leading to poor surface finish

• Reduce speed to reduce temperature
• Reduce feed

• Temperature variations from varying cutting fluid supply or intermittent machining leading to small cracks perpendicular to the cutting edge, insert frittering and poor surface finish

• Apply cutting fluid in large amounts, or not at all
• Reduce cutting speed

Plastic deformation of edge, depression or flank impression leading to poor chip control, poor surface finish and insert breakage.

• Cutting temperature and pressure too high

• Reduce cutting speed
• Reduce feed

Rapid wear causing poor surface finish or out of tolerance.

• The part of the cutting edge which is not in cut is damaged by chip hammering, leading to poor surface and excessive flank wear

• Increase cutting speed
• Reduce feed at the beginning of the cut
• Improve stability
• Increase number of passes
• Use a full-profile insert

Excessive wear resulting in short tool life, burr formation on component, poor surface finish, heat generation and excessive noise.

• Vibration
• Re-cutting of chips
• Burr formation on component
• Poor surface finish
• Heat generation
• Excessive noise

• Increase feed, f_z
• Reduce speed
• Use down-milling
• Evacuate chips effectively using compressed air
• Check recommended cutting data

Uneven wear resulting in corner damage, short tool life, bad surface finish and high noise level.

• Tool run-out
• Vibration
• Short tool life
• Bad surface finish
• High noise level
• Radial forces too high

• Check chuck and collet
• Minimize tool overhang
• Fewer teeth in cut
• Split axial cutting depth, a_p, into more than one pass
• Reduce feed, f_z
• Reduce cutting speed, v_c
• High speed machining requires shallow passes
• Improve clamping of tool and workpiece

• Weak fixturing
• Tool overhang too long

• Check clamping of workpiece and tool
• Minimize overhang
• Check tool holder run out
• Choose a tool with fewer teeth
• Increase number of passes
• Increase feed per tooth
• Reduce cutting speed
• Use up-milling in finishing

• Insufficient chip evacuation

• Use compressed air or large amounts of cutting fluid, preferably through the tool
• Reduce feed per tooth
• Increase number of passes

• Machining work-hardening materials
• Components with skin and scale

• Reduce cutting speed
• Select a tougher grade
• Increase cutting speed

• Machine RPM is too low

• Reduce cutting speed before table speed
• Use a smaller cutter and increase number of passes

• Cutting forces too high

• Reduce tool length
• Use up milling
• Reduce feed
• Increase number of passes
• Use single row insert

• Bad chip evacuation
• Load too big
• Instability

• Use compressed air, emulsion or internal coolant
• Divide cut into 2 or 3 passes
• Reduce feed
• Check/change tool holder