- HY-C Company
- Hy-dit
- Hy-Gain
- HY-KO
- Hy-Lite
- Hy-Pro
- Hy-Tek Manufacturing
- Hybertone
- HYBREX
- HYCHIKA
- Hyco
- HYCON
- Hycontrol
- Hyd-Mech
- Hydac
- HYDAC ELECTRONIC
- HYDAC FILTER SYSTEMS
- HYDAC International
- Hydas
- Hydeline
- Hydor
- Hydra-Cell
- Hydra-Tech
- Hydrajaws
- HydraMaster
- Hydrawise
- Hydrel
- Hydreon
- Hydro
- Hydro Crunch
- Hydro Systems
- Hydro Tek
- Hydro-Force
- Hydro-Gear
- Hydro-Pro
- HYDRO-RAIN
- Hydrofarm
- HYDROLAB
- Hydrolevel
- Hydrologic
- Hydromatic
- Hydromatic Pump