Male to male adapters are used to bridge male to female hoses, pipes or valve fittings. Brass is commonly chosen for corrosion resistance, and is popular with chemical or salt water applications.

Compatible part number - DMH2020F

Note - 2 inch NH / NST is very rare and is often mistaken in place of 1.5 inch NH / NST. When measuring, always try to measure the male coupling! The majority of customers who order 2" NH / NST need 1.5" NH / NST. If you have a fire department connection, hose, or an adapter, check the female coupling for numbers or letters. Most 2.0 inch hoses use 2.0 inch NPSH couplings.

The outside diameter of a 1.5 inch NH / NST male hose coupling or fire hydrant is 1.99 inches. The outside diameter of a 2.0 inch NH / NST male hose coupling or fire hydrant is 2.515 inches. The outside diameter of a 1.5 inch NPT or NPSH male hose coupling is 1.878 inches. The outside diameter of a 2.0 inch NPT or NPSH male hose coupling is 2.352 inches.

WARNING: This product contains a chemical known to the State of California to cause birth defects or other reproductive harm. Do not use in connection with drinking water. Wash hands after handling.

Brass Male to Male Adapter

• Outside diameter of a male GHT adapter: 1 1/16 inches (1.06) - 11.5 Threads per inch
• Garden hose thread is not the same as 3/4 inch pipe thread (NPT)

• 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 inches
• 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: 3 inches
• Outside diameter of a male NH / NST adapter: 3 5/8 inches (3.62) - 6 Threads per inch
• Outside diameter a male NPSH adapter: 3 1/2 inches (3.47) - 8 Threads per inch
• Outside diameter a male NPT adapter: 3 3/8 inches (3.38) - 8 Threads per inch

• 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 adapter: 4 1/2 inches (4.47) - 8 Threads per inch

• Inside diameter of a male adapter: 4 1/2 inches
• Outside diameter of a male NH / NST adapter: 5 3/4 inches (5.76) - 4 Threads per inch
• Outside diameter a male NPSH or NPT adapter: 5 inches (4.97) - 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
• Outside diameter of a male NPSH adapter: 5 9/16 inches (5.56) - 8 Threads per inch
• Outside diameter of a male NPT adapter: 5 7/16 inches (5.44) - 8 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
• Outside diameter of a male NPSH adapter: 6 5/8 inches (6.62) - 8 Threads per inch
• Outside diameter of a male NPT adapter: 6 1/2 inches (6.50) - 8 Threads per inch

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.

• 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

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.

• 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.

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.