USDA Forestry Service fire hose reducer feature aluminum coupling with a 600 PSI test pressure. Meet Forest Service Spec 5100-107. Female 2-1/2" NH, 7 1/2 threads per inch and male 1 1/2" NH, 9 threads per inch. Meets National Fire Equipment System (NFES #2230). Water-Handling Accessories flow rates are 100 PSI flowing pressure.

Fire hose reducer female adapters come with a gasket.

National Stock Number (NSN 4210-01-508-8818)

This Wildland Fire Equipment adapter or coupling is used by the U.S. Forest Service (USFS), Bureau of Land Management (BLM), Bureau of Indian Affairs (BIA), U.S. Fish & Wildlife Service (USF&WS), National Park Service (NPS), State and Local governments, and other Forest Service–sponsored participants in the government-wide wildland firefighting effort.

This is the same water-handling accessories reducer found in the Defense Logistics Agency (DLA) Wildland Fire Equipment catalog or Fedmall.mil.

The Safe Water Drinking Act section 1417 requires "Lead-Free" products to be a minimum of 99.75% lead-free.

Download Spec Sheet

• Made in USA
• Female Side: 2 1/2 inch NH / NST
• The Female Will Only Connect to a Male 2 1/2 inch NH / NST
• Male Side: 1 1/2 inch NH / NST
• The Male Will Only Connect to a Female 1 1/2 inch NH / NST
• Material: 6061-T6 Aluminum
• Finish: Hard Coat Anodized
• Complies With NFPA 1963 (Corrosion Resistance)
• 99.95% Lead Free
• See SKU B37P2515 for Brass Version

• Outside diameter of a male GHT adapter: 1 1/16 inches (1.06) - 11.5 Threads per inch

• Inside diameter of a male adapter: 1 inch
• Outside diameter of a male NH / NST adapter: 1 3/8 inches (1.375) - 8 Threads per inch
• Outside diameter a male NPSH or NPT adapter: 1 5/16 inches (1.295) - 11.5 Threads per inch

• Inside diameter of a male adapter: 1 1/2 inches
• Outside diameter of a male NH / NST adapter: 2 inches (1.99) - 9 Threads per inch
• Outside diameter a male NPSH or NPT adapter: 1 7/8 inches (1.87) - 11.5 Threads per inch

• 1 3/4 inch hoses come with 1 1/2 inch couplings

• Inside diameter of a male adapter: 2 inch
• Outside diameter of a male NH / NST adapter: 2 1/2 inches (2.51) - 8 Threads per inch
• Outside diameter a male NPSH or NPT adapter: 2 3/8 inches (2.35) - 11.5 Threads per inch

Note - 2 inch NH or NST is very rare. If the outside diameter of male adapter is approximately two inches, you need 1 1/2 inch NH or NST.

• Inside diameter of a male adapter: 2 1/2 inches
• Outside diameter of a male NH / NST adapter: 3 1/16 inches (3.06) - 7.5 Threads per inch
• Outside diameter a male NPSH or NPT adapter: 2 7/8 inches (2.84) - 8 Threads per inch

• Most 3 inch hoses come with 2 1/2 inch couplings

• Inside diameter of a male adapter: 4 inches
• Outside diameter of a male NH / NST adapter: 5 inches (5.01) - 4 Threads per inch
• Outside diameter a male NPSH or NPT adapter: 4 1/2 inches (4.47) - 8 Threads per inch

• Inside diameter of a male adapter: 5 inches
• Outside diameter of a male NH / NST adapter: 6 1/4 inches (6.26) - 4 Threads per inch

• Inside diameter of a male adapter: 6 inches
• Outside diameter of a male NH / NST adapter: 7 1/32 inches (7.025) - 4 Threads per inch

• The female side of a NH / NST coupling will only connect to a male NH / NST connection
• The male side of a NH / NST coupling will only connect to a female NH / NST connection
• The female side of a NPSH coupling will only connect to a male NPT pipe or a male NPSH connection
• The male side of a NPSH coupling will only connect to a female NPSH connection. It will NOT thread into a female NPT pipe. For example, a male NPSH coupling will NOT thread into a female metal or pvc pipe.
• The female side of a garden hose will only connect to a male garden hose connection.
• The male side of a garden hose will only connect to a female garden hose connection.

NH / NST: The most common thread type in use by fire departments today is NST or National Standard Thread. NST also goes by the initials NH or National Hose. It can even be referred to as NHT or National Hose Thread but NST or NH is more common these days. NH = NST.

NPSH: National Pipe Straight Hose (NPSH) or Iron Pipe Thread (IPT) has the same threads per inch (TPI) as National Pipe Tapered (NPT) but the thread does not taper. NPSH is a straight thread and seals by a gasket in the female coupling which allows for a swivel, just like NH / NST, which make both ideal for hose couplings.

NPT: National Pipe Tapered is common in plumbing and some industrial uses. Sometimes referred to as pipe thread because PVC pipe and schedule 40 pipe are typically threaded in NPT. As its name implies this is a tapered thread so that the outside diameter of the male (ODM) gets smaller towards the end of the fitting and the inside diameter of the female narrows with depth. As the two fittings are threaded together the opposite tapers force thread friction and makes the seal without the use of a gasket.

Limited Lifetime Warranty - We will replace any adapters with manufacturer defects in material and workmanship. All warranty claims must be returned to us for inspection before we determine a solution.

Our warranty does not cover gaskets, multiple use of NPT threads, shipping cost, cosmetic damages, normal wear-and-tear, improper use or chemical damage.

Adapters purchased for use at Fire Training Facilities will have a 90-day Manufacturer Defect warranty only.