Hose Thread Size Chart

Tired of leaky hoses and frustrating mismatches? Our comprehensive Hose Thread Size Chart shows you exactly which hose fits your specific needs. From garden hoses to pressure washers, find the perfect connection every time!

Garden Hose Thread Size Chart

While garden hoses come in various inner diameters (⅜”, ½”, ⅝”, and ¾”), the threads on the couplings are standardized for easy connection.

Standard Thread:

Name: American National Standards Institute (ANSI) standard for garden hose fitting thread size

Designation: ¾”–11.5 NH or NHR

Description: This is the one standard size for threads on both male (hose end) and female (spigot end) connectors in North America.

Details:

Outer thread diameter: 1.0625 inches (approx. 27mm)
Thread pitch: 11.5 threads per inch (TPI)

Fire Hose Thread Size Chart

Fire hose threads are more complex than garden hose threads, with several variations in size and design. Here’s a breakdown to help you navigate fire hose thread sizes:

Standard Fire Hose Thread:

Name: National Standard Thread (NST)
Description: The most common thread type for fire hoses in the United States. It’s a straight-walled thread, unlike the tapered threads used in plumbing.
Size: Designated by nominal diameter (e.g., 2.5″ NST) which refers to the approximate inside diameter of the hose when connected.

Hose thread Abbreviations

Abbreviations
NPTF	National Pipe Tapered Fuel
NPSM	National Pipe Straight Mechanical
ISO	International Standards Organization
SAE	Society of Automotive Engineers
JIC	Joint Industrial Council
NFPA	National Fluid Power Association
BSP	British Standard Pipe
DIN	Deutsche Industrial Norme
JIS	Japanese Industrial Standard
BSPT	British Standard Pipe Tapered
BSPP	British Standard Pipe Parallel

National Pipe Tapered Fuel (NPTF)

National Pipe Tapered Fuel (NPTF) threads are a type of pipe thread standard designed for creating a leak-proof seal for liquids and gases, particularly fuels and oils.

Key Characteristics of NPTF threads:

Tapered design: Similar to NPT (National Pipe Thread), NPTF threads have a tapered design that creates a tighter seal as the connection is made.
Fuel-tight seal: Unlike NPT threads, which often require sealant tape for leak prevention, NPTF threads are designed for a metal-to-metal seal, eliminating the need for additional sealant in most applications. This is achieved by slightly different dimensions at the root and crest of the threads compared to NPT.
Standardization: NPTF threads are standardized by the American National Standards Institute (ANSI) under designation ANSI B1.20.3.

National Pipe Tapered Fuel (NPTF) Thread Size Chart

NPTF threads are commonly used for fuel and hydraulic connections. Here’s a chart listing common sizes:

Inch Size	Dash Size	Threads per Inch (TPI)	Male Thread O.D. (in)	Female Thread O.D. (in)
1/16	–	27	0.3125	0.2611
1/8	–	27	0.405	0.401
1/4	–	18	0.540	0.534
3/8	–	18	0.675	0.641
1/2	–	14	0.840	0.821
3/4	–	14	1.050	1.036
1	–	11.5	1.315	1.291
1¼	–	11.5	1.660	1.636
1½	–	11.5	1.900	1.876
2	–	11.5	2.375	2.351

National Pipe straight mechanical (NPSM)

National Pipe Straight Mechanical (NPSM) threads provide a mechanical connection for pipes, typically requiring an additional sealing mechanism like an O-ring for leak prevention. Here’s a breakdown of NPSM threads:

Function:

Creates a secure mechanical joint between pipes.
Relies on an additional sealing element (e.g., O-ring) for leak prevention, unlike tapered NPT threads that create a seal on their own.

Dimensions:

Shares the same thread pitch (TPI) as National Standard Thread (NST) used in fire hoses (typically 11.5 TPI for larger sizes).
Maintains a straight wall profile unlike the tapered design of NPT threads.
Specific dimensions (diameter, thread allowance) are outlined in the ANSI/ASME B1.20.1 standard.

Here’s a National Pipe Straight Mechanical (NPSM) Thread Size Chart with common sizes, including Inch Size, Threads per Inch (TPI), Male Thread O.D. (Outer Diameter), and Female Thread I.D. (Inner Diameter).

Note: Dash size is not used with NPSM threads.

Inch Size	Threads per Inch (TPI)	Male Thread O.D. (in)	Female Thread I.D. (min) (in)
1/8	27	0.397	0.358
1/4	18	0.526	0.468
3/8	18	0.662	0.603
1/2	14	0.823	0.747
3/4	14	1.034	0.958
1	11.5	1.293	1.201
1¼	11.5	1.638	1.546
1½	11.5	1.877	1.785
2	11.5	2.351	2.259
2½	8	2.841	2.708
3	8	3.467	3.334
4	8	4.466	4.333
5	8	5.528	5.395
6	8	6.585	6.452

JIC 37° Flare (SAE J514)

JIC 37° Flare (SAE J514) is a type of fitting commonly used in hydraulic systems. It utilizes a 37° flare on the male fitting that seals against a matching female flare seat. The straight threads hold the connection together mechanically.

JIC 37° Flare fittings come in various sizes designated by a dash number, which corresponds to the tubing outside diameter (OD). Here’s a table outlining some common JIC sizes and their corresponding dimensions:

Dash Size	Inch Size	Thread	Male Thread OD (mm)	Male Thread OD (in)	Female Thread ID (mm)	Female Thread ID (in)
2	1/8	5/16-24*	7.9	0.31	6.9	0.27
4	1/4	7/16-20*	10.3	0.41	9.3	0.37
6	3/8	1/2-18*	12.7	0.50	11.7	0.46
8	1/2	9/16-18*	16.7	0.66	15.7	0.62
10	5/8	3/4-16*	19.1	0.75	18.1	0.71

*Note that most SAE J514 threads have the same dimensions as SAE 45° flare threads, except for the crucial difference in the flare angle. It’s important not to interchange these two types of fittings due to their incompatibility.

SAE 45° Flare (SAE J512)

SAE 45° Flare (SAE J512) is another popular fitting standard used for low-pressure applications like refrigerant and fuel lines. Similar to JIC 37° Flare, it utilizes a flared connection for sealing but with a 45° angle on the male fitting, instead of 37°.

Here’s what you need to know about SAE 45° Flare thread sizes:

Sizing: SAE 45° Flare fittings use a combination of a dash size and a nominal tube diameter (in inches) to designate size. The dash size corresponds to the tubing outside diameter (OD).
Thread Specifications: The threads themselves conform to the Unified National Coarse (UNC) thread standard, with specific thread sizes for each fitting.

Here’s a table summarizing some common SAE 45° Flare sizes:

Dash Size	Nominal Tube Size (in)	Threads per Inch	Male Thread OD (in)
2	1/8	24	0.625
4	1/4	20	0.812
6	3/8	18	1.000
8	1/2	14	1.313
10	5/8	14	1.625
12	3/4	14	1.938

Important Note: While some SAE 45° Flare fittings share the same thread dimensions as JIC 37° Flare (sizes 7/16-20, 1/2-20, 3/4-16 & 7/8-14), they are not interchangeable due to the different flare angles (45° vs 37°). Make sure to use the correct fitting type for your application.

For a more comprehensive list of SAE 45° Flare thread sizes and specifications, you can refer to resources like the SAE J512 standard or online thread charts provided by fitting manufacturers.

SAE 45° Flare (SAE J512)

Here’s what you need to know about SAE 45° Flare thread sizes:

Sizing: SAE 45° Flare fittings use a combination of a dash size and a nominal tube diameter (in inches) to designate size. The dash size corresponds to the tubing outside diameter (OD).
Thread Specifications: The threads themselves conform to the Unified National Coarse (UNC) thread standard, with specific thread sizes for each fitting.

Here’s a table summarizing some common SAE 45° Flare sizes:

Dash Size	Nominal Tube Size (in)	Threads per Inch	Male Thread OD (in)
2	1/8	24	0.625
4	1/4	20	0.812
6	3/8	18	1.000
8	1/2	14	1.313
10	5/8	14	1.625
12	3/4	14	1.938

For a more comprehensive list of SAE 45° Flare thread sizes and specifications, you can refer to resources like the SAE J512 standard or online thread charts provided by fitting manufacturers.

Hydraulic Hose

Industrial Hose

Hose Protection

Hydraulic Hose Fitting

PVC Hose

Hose Thread Size Chart

Garden Hose Thread Size Chart

Fire Hose Thread Size Chart

Hose thread Abbreviations

National Pipe Tapered Fuel (NPTF)

National Pipe Tapered Fuel (NPTF) Thread Size Chart

National Pipe straight mechanical (NPSM)

JIC 37° Flare (SAE J514)

SAE 45° Flare (SAE J512)

SAE 45° Flare (SAE J512)

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