re: #175 sattv4u2

Actually, it is

In film, it’s a sign to cut the scene (stop the filming)
Out in the field, with heavy equipment operators, it’s a sign to cut the engine (or stop the process ,, i.e. drilling, or stopping a fork lift,, or backing up a truck)

You are correct.
Understanding Various Hand Signals When Producing A Video Or Film

Cut/Stop:

Although sometimes verbalized, the hand signal for actors to stop performing involves the floor manager using his hand in a motion as if to cut his own neck. Sometimes the supervisor or director, if on the set, may simply yell out cut because during editing the recording would be stopped just before the verbal connotation