Troubleshooting Guide

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Tap Does Not Start

Check the following:

Program depth:

• Compression stroke may use up the entire program depth.
  
  

Tap drill size:

• Check for tap drill size.
  
  

Tap sharpness:

• Check for dull tap.
  
  

Premature Torquing of Unit

Check the following:

Tap sharpness:

• Dull taps require more driving torque than sharp taps. NUMERTAP systems sense dull taps. Replace to prevent possible breakage.
  
  

Tap drill size and adequate drill depth:

• Check for correct size and depth.
  
  

Tap sharpness:

• Check for dull tap.
  
  

Oversized Threads

Check the following:

Feeds and speeds:

• Oversized threads mean that the space between adjacent teeth is too large. This is caused either by forcing or retarding the feed rate with respect to the speed. Check program feed versus tap pitch.
  
  

Tension stroke of tapping head:

• Check to ensure that the tension stroke does not stick.
  
  

Poor Thread Quality

Check the following:

Feeds and speeds:

• Oversized threads mean that the space between adjacent teeth is too large. This is caused either by forcing or retarding the feed rate with respect to the speed. Check program feed versus tap pitch.
  
  

Tap sharpness and condition:

• Check for dull tap or broken teeth. Replace as required.
  
  

Consult NUMERTAP Tap Guide for proper tapping speeds, lubricants, geometry, and tap drill sizes for specific H limits and specific materials. If you are not using NUMERTAP taps, consult the tap manufacturer.