- rotary boiler
- rotary bushing
- rotary hose
- rotary oiler
- rotary washer
- rotation rate
- rotten ice
- rougemontite
- rough analysis
- roughness
- roundbar iron
- royal paulowina
- Royalties
- royalty interest
- rub fastness
- rubber asphalt
- rubber gasket
- rubber seal
- rubber sponge
- rubellite
- ruberythic
- rudaceous structure
- run gravel
- run in
- rundown line
- runner basin
- rupture load
- rupture test
- rust film
- rust protection
- rust-ban
- rustproof finish
- sack paper
- sacklite structure
- sacrificial anode
- saddle axis
- saddle leather
- safeguard
- safety allowance
- safety dog
- safety fuse
- safety glass
- safety lock
- safety record
- safety slide
- sag
- sage oil
- roundness ratio
- roustabout
- rouvillite
- royal jelly
- royalty
- royalty deed
- rubber
- rubber cement
- rubber composition
- rubber dissolution
- rubber goods
- rubber grease
- rubber mill
- rubber packing
- rubber solvent
- rubber thread
- rubberized
- rubberized cloth
- rubble
- ruben cell
- ruby glass
- rudyte
- rundown tank
- runner
- running clearance
- Ruska porosimeter
- rustproofing
- sabuline
- sabulous
- rudite
- run
- running meter
- rutherfordite
- sabulite
- saccharine
- saccharoidal texture
- sad colored
- saddle flange
- saddle reef
- saddle tee
- saddle vein
- safe dose
- safe operation
- safety board
- safety cartridge
- safety head
- safety joint
- safety loop
- safety platform
- sagging
- sago
- Sahelian stage
- salacetol