- fixed fire extinguisher
- fixed focal length photographic lens
- fixed foundation for offshore wind turbines
- fixed frame
- fixed function
- fixed gamma spectrometer
- fixed gillnet fishing
- fixed growth stock valuation model
- fixed guard
- fixed homeomorphism
- fixed index
- fixed Intelligent monitoring
- fixed interest
- fixed-interual schedule
- fixed interval
- fixed-interval schedule
- fixed-interval smoother filter algorithm
- fixed length
- fixed length subnetting
- fixed level
- fixed line
- fixed-load speedup
- fixed manifold
- fixed mapping
- fixed matrix