help - hors
- helper
- helve
- hematite
- hemispherical combustion chamber
- hemp belt
- hemp packing
- hemp rope
- hempseed oil
- henry
- herf
- hermetic
- herringbone gear
- herringbone gear pump
- herringbone tooth
- hesselman engine
- heterogeneity
- heterogeneous material
- heterogeneous reactor
- heteropolar generator
- hex bolt
- hex head screw
- hexadecimal number
- hexadecimal system
- hexagon bar
- hexagon bolt
- hexagon head
- hexagon head bolt
- hexagon nut
- hexagon socket head
- hexagon socket head screw
- hexagon spanner
- hexagon wrench
- hexagonal lattice
- hidden arc welding
- hidden line
- hierarchical control
- hierarchy
- high alloy steel
- high altitude engine
- high capacity press
