- spectrochemistry
- spectroscope
- speed counter
- spent catalyst
- spent fuel
- spent residue
- spheroid tank
- spheroidal graphite
- spheroidal weathering
- spherulitic structure
- spider slip
- spilitic
- spill
- spillage
- spindle capacity
- spindle oil
- spinner
- spinning
- spinning machine
- spinning process
- spider
- spider gear
- spiegel iron
- spigot bearing
- spilling
- spinning cathead
- spinning chain
- spinning pot
- spinodal decomposition
- spiral guide
- spiral nebular
- spiral welding
- spirant
- spire
- spirit
- spirt
- spit
- splicing needle
- splintery fracture
- split ring
- split sleeve
- split test
- spodumene
- spoilage
- sponge rubber
- spongy
- spongy structure
- spontaneous change
- spontaneous ignition
- spontaneous magnetization
- spool piece
- spotted slate
- spouting spring
- spray combustion
- spray gun
- spray oil
- spray test
- spray tower
- spread correction
- spread superintendent
- spring shackle
- Springerian stage
- sprinkle
- sprinkler
- spruce
- sprue gate
- sprung mass
- spudding in
- spur gear
- square foot
- square joint
- square yard
- spirit level
- spitting
- splash feed
- splint coal
- split brick
- split group
- sponge
- sponge grease
- spongy metal
- spongy texture
- spontaneous combustion
- spontaneous heating
- spontaneous process
- spontaneous reaction
- spool
- spooling flange
- spore coal
- spot chartering
- spot test
- spotted schist
- stabbing board
- stabilization
- stabilizer
- stabilizer plant
- stable emulsion
- stable mineral
- stack gas
- stack loss