THREADING SOLUTIONS 
Problem Cause Solutions
Thread cutting • Incorrect thread cutter
• Incorrect tolerance
• Thread cutter is not centered
• Cutting speed is too high
• Insufficient lubricating coolant delivery
• Core hole bore is too small
• Chipping blockage
• Incorrect axial feed rate selected
• Match the thread cutter to the correct material group
• Check the tolerance of the thread cutter and, if applicable, use another tool
• Check tool mount and position the center of the thread cutter over the hole
• Reduce cutting speed
• Ensure good lubricating coolant delivery
• Ensure that the correct core hole bore is used (see core hole drill table)
• Use the correct tool shape
• Reduce feed rate to 5-10% and check the contact pressure of the thread cutter
Thread is too narrow • Incorrect thread cutter
• Incorrect tolerance
• Core hole bore is too small
• Thread is too narrow
• Match the thread cutter to the correct material group
• Check the tolerance of the thread cutter and, if applicable, use another tool
• Ensure that the correct core hole bore is used (see core hole drill table)
• Ensure that the correct tool shape is used
Too much wear • Incorrect thread cutter
• Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Cutting speed is too high
• Match the thread cutter to the correct material group and select the correct shape
• Ensure good lubricating coolant delivery
• Ensure correct lubricating coolant composition
• Reduce cutting speed
Tool chipping off • Incorrect thread cutter
• Hardened surface
• Core hole bore is too narrow
• Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Match the thread cutter to the correct material group and select the correct shape
• Reduce speed, choose a coated tool,
• Ensure good lubricating coolant composition
• Ensure that the correct core hole bore is used (see core hole drill table)
• Ensure good lubricating coolant delivery
• Ensure correct lubricating coolant composition
Thread surface is not clean • Chipping blockage
• Cold welding on the thread cutter flank
• Unsuitable tool shape
• Cutting speed is too high
• Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Ensure that the correct tool shape is used
• Remove cold welding or use another tool
• Ensure the correct thread cutter is used
• Reduce cutting speed
• Ensure good lubricating coolant delivery
• Ensure correct lubricating coolant composition
Thread cutter breakage • Chip blockage or jam
• Tool shape unsuitable for the work
• Too much wear on the thread cutter
• Torque is too high
• Thread core hole is too narrow
• Adapt choice of thread cutter to the work being carried out
• Ensure that the correct tool shape is used
• Replace the thread cutter in good time
• Use a thread cutter with overload coupling
• Ensure that the correct core hole bo
Thread cutter overheating • Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Thread cutter is worn
• Ensure good lubricating coolant delivery
• Ensure correct lubricating coolant composition
• Replace the thread cutter in good time
Thread axially blended • Obtain left-rotating thread cutter for lower point pressure
• Strong right-rotating thread cutters have point pressure that is too strong
• Keep thread cutter in the same pressure range as the thread cutter chuck. Stronger axial contact pressure when beginning to cut
• Only minimum contact pressure when beginning to cut