door - drop
- double-stoppered ladle
- double-strand
- double-strand casting
- double-strand conveyor
- double-strand drag conveyor
- double-strand mill
- double-strand plant
- double-strand twisting
- double-suction ventilator
- double-swivel ing recoiler
- double-swivelling recoiler
- double-track skip hoist
- double-transceiver technique
- double-transducer ultrasonic test
- double-trial-and-error method
- double-U (butt) groove
- double-U butt weld
- double-u groove weld
- double-V (butt) groove
- double-V butt weld
- double-v groove weld
- double-V-type goggle valve
- double-wall funnel
- double-wall technique
- double-wave detection
- double-welded joint
- doubler
- doubles
- doublet (energy) level
- doublet component
- doublet interval
- doublet term
- doubling effect
- doubling machine
- doubling of line
- doubling of sheets
- doubly curved crystal
- doubly curved surface
- doubly degenerate
- doubly ionized atom