- reduction gear
- reduction number
- reduction process
- Redwood viscosity
- reef belt
- reef breccia
- reef edge
- reef facies
- reef limestone
- reefing
- reel
- reference test
- refine
- refined tar
- refining method
- reflection pattern
- reflow soldering
- reflux
- reflux drum
- reflux ratio
- reformed gasoline
- refraction shooting
- refractivity
- refractory
- refractory lining
- refrigerant outlet
- refrigeration oil
- regional dip
- registered design
- regosol
- regular gasoline
- regular joint
- regular mud
- regular oil
- regular rayon
- regular system
- Reich process
- reinforcing agent
- reinforcing filler
- reinforcing pad
- relative intensity
- relativism
- relativistic anomaly
- relaxation center
- relaxation time
- release agent
- releasing spear
- relic lake
- reheater
- reinforcement coating
- rejuvenate
- relative density
- release
- relic structure
- relief cock
- relieve
- relieving
- reload
- remaking
- remalloy
- remanent magnetization
- remelting
- remelting process
- remodel
- reference gage
- reference liquid
- refined hydrocarbons
- refinement
- refinery sludge
- refining license
- refinishing
- reflecting horizon
- refloat
- reflux exchanger
- refluxing
- refolding
- reforming
- refrigerant layer
- refuse dump
- regenerated
- register
- registration paper
- Regressive tax
- regrinding
- removable liner
- removal
- remove
- remover
- removing
- renardite
- rending effect
- renewable fuel
- Renewable resource
- rengas
- reniform
- rennin
- rent
- rental
- reopened vein
- repair pit