- Heat sinks
- Heat transfer
- Heat transfer coefficient
- Heat treating
- Heat-transfer fluid
- Heater core
- Heating elements
- Heavy crude oil
- Heavy equipment
- Heavy metals
- Heavy water
- Hectare
- Hectorite
- Helicopter rotor
- Helicopters
- Heliox
- Helium
- Helium-3
- Helium-4
- Hematite
- Hemicellulose
- Hemimorphite
- Hemocyanin
- Hemodialysis
- Hemodynamics
- Hemoglobin
- Hemolytic anemia
- Hemoptysis
- Hemozoin
- Henry's Law
- Hepatitis
- Hepatitis A
- Hepatitis E
- Heptane
- Hermetic seal
- Heron's formula
- Herringbone pattern
- Hertz
- Hertzian cone
- Heteroatoms
- Heterocyclic compounds
- Heterodyne
- Heuristics
- Hexachloroethane
- Hexafluoropropylene
- Hexagonal lattice
- Hexagons
- Hexamethylenetetramine
- Hexane
- Hexavalent chromium
- High frequency
- High-density polyethylene
- High-energy x-rays
- High-level waste
- High-performance plastics
- High-resolution computed tomography
- High-speed steel
- High-strength low-alloy steel
- High-temperature corrosion
- High-temperature gas-cooled reactor
- High-temperature superconductivity
- Higher alkanes
- Highway engineering
- Hildebrand solubility parameter
- Hinges
- Hip replacement
- Histogram
- Hoffmann kiln
- Hogging and sagging
- Hollandite
- Homeostasis
- Homochirality
- Homogeneity
- Homogeneous spaces
- Homologous series
- Homologous temperature
- Homolysis
- Honeycomb structures
- Hooke's Law
- Hopcalite
- Hopeite
- Hornblende
- Hornfels
- Horsepower
- Hot air balloons
- Hot blast
- Hot springs
- Hot working
- Hot-dip galvanization
- House
- Hovercraft
- Human body
- Human brain
- Human error
- Human nose
- Human skeleton
- Human-powered aircraft
- Humidistat
- Humidity
- Huntite
- Hybrid materials
- Hydrate
- Hydration energy
- Hydraulic accumulators
- Hydraulic brake
- Hydraulic conductivity
- Hydraulic cylinders
- Hydraulic engineering
- Hydraulic fluid
- Hydraulic lime
- Hydraulic mining
- Hydraulic presses
- Hydraulic pump
- Hydraulic ram
- Hydraulics
- Hydrazine
- Hydrazinium
- Hydrazoic acid
- Hydrides
- Hydrocarbon mixtures
- Hydrocarbons
- Hydrochloric acid
- Hydrochloric acid regeneration
- Hydrochloride
- Hydrodealkylation
- Hydrodemolition
- Hydrodesulfurization
- Hydroelectricity
- Hydrofluoric acid
- Hydrofluorocarbons
- Hydroforming
- Hydrogels
- Hydrogen atom
- Hydrogen bonds
- Hydrogen chloride
- Hydrogen economy
- Hydrogen embrittlement
- Hydrogen halides
- Hydrogen ions
- Hydrogen peroxide
- Hydrogen production
- Hydrogen sulfide
- Hydrogenase
- Hydrogenation
- Hydrogenolysis
- Hydrogeology
- Hydrography
- Hydrohalite
- Hydrology
- Hydrolysis