Siemens alarm 10601: Channel %1 block %2 zero velocity at block end point during thread cutting

What it means

During thread cutting the path velocity at the end of the thread block must remain above zero, otherwise the tool stalls in the material and the pitch is ruined. The control detected that the commanded feed falls to exactly zero at the block end point. This typically happens when the feed value is too small for the programmed thread length.

Likely causes

• Feedrate F far too small relative to thread length
• Feed override reduced toward 0% during tapping/threading
• Very short thread block combined with lead-change values