Initialism of National Hose thread, also known as National Standard Thread. It dictates the pitch and diameter of the threads on hose couplings, nozzles, and hydrants to ensure equipment from different departments connects without adapters. The specification prevents the historic problem of mutual aid companies arriving at a fire and being unable to connect to local water supplies.
Heard on the job
Make sure you grab the adapter, that mutual aid department doesn't run NH on their hydrants.
Insider tip
Always check local thread types when operating outside your home jurisdiction, as some older cities still use proprietary threads instead of the NH standard.
Also heard as
- National Hose
- National Standard Thread
Do not mix it up with
- NST: NH and NST refer to the exact same thread standard and are used interchangeably.