- Sacrificial Anode
- Sandwich Panel
- Saturation
- Scanning Electron Microscopy (SEM)
- Scanning Probe Microscope
- Schottky Defect
- Scission
- Screw Dislocation
- Secondary Bond
- Selective Leaching
- Self Diffusion
- Self Interstitials
- Semiconductor
- Shear Stress
- Shear Strain
- Single Crystal
- Sintering
- Slip (Plastic Deformation)
- Slipcasting
- Slip System
- Softening Point (glass)
- Soft Magnetic Materials
- Soldering
- Solid solution
- Solid Solution Strengthening
- Solidus Line
- Solute
- Solution Heat Treatment
- Solvent
- Solvus Line
- Specific Heat
- Specific Modulus
- Specific Strength
- Spheroidite
- Spherulites
- Spheroidizing
- Spinning
- Stabilizers
- Stainless Steel
- Standard Elctrode Potential
- Steady-state Diffusion
- Stereoisomerism
- Stereochemistry
- Strain Hardening
- Strain Point (Glass)
- Stress Concentration
- Stress Corrosion
- Stress Riser
- Structural Clay Products
- Substitutional Solid Solution
- Superconductivity
- Supercooling
- Superheating
- Syndiotactic