forelocked bolt - fuel up
- free-carrier plasma
- free-convection heat transfer
- free-cutting
- free-cutting steel
- free-drop catch
- free-fall
- free-fall model
- free-fall test
- free-falling classifier
- free-flight
- free-flight missile
- free-flight model
- free-flight projectile range
- free-flight rocket
- free-flight wind tunnel
- free-floating
- free-floating roller
- free-flow conduit
- free-flowing channel
- free-free transition
- free-jet type turbine
- free-jet wind tunnel
- free-melting
- free-piston compressor
- free-piston engine
- free-roller gate
- free-rolling flight
- free-running
- free-running fit
- free-running frequency
- free-running laser
- free-running mode
- free-running multivibrator
- free-running operation
- free-running slag
- free-space
- free-space attenuation
- free-space range
- free-space wavelength
- free-springing nappe
