Lead
Lead turns up in 2 fields: fasteners, electrotechnology. Here is what it means to the people in each one.
Lead in fasteners
The distance a thread advances along its axis in one full turn, equal to pitch times the number of starts.
The axial travel of a screw or nut per revolution. For an ordinary single-start fastener, lead equals pitch; a double-start thread has a lead of twice its pitch, so it moves twice as far per turn with the same thread depth. Multi-start threads appear on bottle caps, quick-acting closures, valve stems and lead screws, and they are less self-locking than single-start threads of the same pitch.
"It's a two-start thread, so the lead's double the pitch, that's why the cap spins on so fast."
Lead in electrotechnology
The condition where the alternating current waveform arrives ahead of the voltage waveform.
In alternating current circuits, lead occurs when the phase angle of the current waveform precedes the voltage waveform. This is typically caused by capacitive loads in the system, which draw current before the voltage peaks. Power engineers monitor leading power factors because excessive lead can cause overvoltages and instability on the grid.
"We have too much lead on this feeder, so bring another reactor online to absorb the vars."