one- - over
- one-base silicate
- one-deck oven
- one-degree structure
- one-dimensional optical grating
- one-fold axis
- one-head
- one-leg construction gantry crane
- one-lip (hand) ladle
- one-man molding box
- one-motor traveling crane
- one-motor travelling crane
- one-of-a-kind casting
- one-operator vertical welding
- one-pass operation
- one-pass rolling
- one-pass welding
- one-phase alloy
- one-phase two-electrode furnace
- one-piece
- one-piece bridge die
- one-piece casting
- one-piece die
- one-piece hopper
- one-piece male punch
- one-piece nozzle
- one-piece pattern
- one-piece welded frame
- one-side transfercar
- one-sided nugget
- one-step
- one-story furnace
- one-strand continuous casting machine
- one-strand rolling
- one-way fired (soaking) pit
- one-way lubricating system
- one-way scoop feeder
- ONIA-Novalfer process
- onset of transformation
- oolites
- oolitic
