Symbol 6007 from IEC 60417 - Title/Meaning: Hot start Function/description: To identify the control or function increasing the energy at the beginning of the weld.
Additional information: 
Control is identified by one of letter chosen in IEC 60974-1, Table L.1.
The meaning of the graphical symbol depends on its orientation.
Own work using: iso.org/obp/graphics/grs/761fde78-8e7e-4a16-9e10-cb25e3cee323 200.png
Vectorization:  Mrmw