Pipe Fittings
Hex Nipple
316 stainless steel hex nipple for connecting two female-threaded ports in instrumentation, process and industrial fluid systems. Available in equal and reducing configurations with NPT and selected ISO/BSP, Unified (SAE) and metric thread combinations.
Specifications
- Series
- THN Series
- Fitting Type
- Hex Nipple
- Configuration
- Straight Male × Male
- Primary Thread
- NPT
- NPT Standard
- ASME B1.20.1
- Available Thread Types
- NPT, ISO/BSP Tapered, ISO/BSP Parallel, Unified (SAE) and Metric
- NPT Size Range
- /16 to 2 in., depending on configuration
- Standard Material
- 316 Stainless Steel
- Material Specification
- ASTM A276 Bar Stock
- Body Construction
- Machined from Bar Stock
Overview
The THN Series Hex Nipple is a straight male-to-male pipe fitting used to connect two female-threaded ports or components.
The central hex provides wrench engagement during installation, while the two male threaded ends allow direct connection between components without a separate coupling. Equal-size configurations connect matching thread sizes, while reducing configurations provide a transition between different sizes.
NPT is the primary thread configuration. Selected combinations with ISO/BSP tapered, ISO/BSP parallel, Unified (SAE) and metric threads are also available for systems requiring transitions between different thread standards.
Key Features
- Straight male-to-male pipe connection
- Equal and reducing configurations
- Central hex for wrench installation
- NPT threads based on ASME B1.20.1
- Selected mixed-thread configurations available
- NPT sizes from 1/16 to 2 in., depending on configuration
- 316 stainless steel as the standard material
- Straight body machined from bar stock
- Suitable for instrumentation, process and industrial fluid systems
Engineering Specifications
Parameter | Specification |
|---|---|
Product Type | Hex Nipple |
Series | THN |
Body Style | Straight |
Connection | Male Thread × Male Thread |
Primary Thread Type | NPT |
NPT Standard | ASME B1.20.1 |
Available Thread Types | NPT, ISO/BSP Tapered, ISO/BSP Parallel, Unified (SAE) and Metric |
NPT Size Range | 1/16 to 2 in., depending on configuration |
Standard Material | 316 Stainless Steel |
Material Specification | ASTM A276 Bar Stock |
Working Pressure | Size and configuration dependent |
Heavy-Wall Option | Available in selected NPT sizes |
NPT Size & Working Pressure
Standard equal-size Male NPT × Male NPT configurations in 316 stainless steel are available with the following working-pressure ratings:
NPT Size | Working Pressure |
|---|---|
1/16 in. | 11,000 psi / 757 bar |
1/8 in. | 10,000 psi / 689 bar |
1/4 in. | 8,000 psi / 551 bar |
3/8 in. | 7,800 psi / 537 bar |
1/2 in. | 7,700 psi / 530 bar |
3/4 in. | 7,300 psi / 502 bar |
1 in. | 5,300 psi / 365 bar |
1 1/4 in. | 6,000 psi / 410 bar |
1 1/2 in. | 5,000 psi / 344 bar |
2 in. | 3,900 psi / 268 bar |
Working-pressure ratings vary with thread size, thread combination, material and configuration. The allowable working pressure of a complete system is limited by its lowest-rated component and the applicable operating conditions.
Heavy-Wall Configurations
Selected equal-size Male NPT × Male NPT configurations are available with a heavy-wall construction for higher-pressure requirements.
Available heavy-wall sizes include:
- 1/4 in.
- 3/8 in.
- 1/2 in.
- 3/4 in.
- 1 in.
These listed heavy-wall configurations are rated up to 10,000 psi / 689 bar in 316 stainless steel.
Thread Configurations
Available configurations include:
- Male NPT × Male NPT
- Male NPT × Male ISO/BSP Tapered
- Male NPT × Male ISO/BSP Parallel
- Male NPT × Male Unified (SAE)
- Male NPT × Male Metric
- Male Metric × Male Metric
Available sizes and combinations depend on the selected thread standards and fitting configuration.
Thread & Sealing Considerations
NPT is a tapered pipe thread. Sealing is developed through thread engagement together with a thread-sealing method appropriate for the fluid, temperature and operating conditions.
ISO/BSP tapered threads also use a tapered-thread sealing principle, while parallel and straight-thread connections require a sealing arrangement appropriate to the specific connection design.
Thread systems should not be selected solely by nominal diameter. Thread standard, pitch, taper or parallel form, mating connection and sealing method should all be verified before ordering.
Material
Standard Material: 316 Stainless Steel
THN Series straight fittings are machined from 316 stainless steel bar stock to ASTM A276.
316 stainless steel provides corrosion resistance and mechanical performance for a wide range of instrumentation, process and industrial fluid applications.
Typical Applications
Hex Nipples are commonly used in:
- Process control systems
- Pressure and flow instrumentation
- Valve and manifold connections
- Pumps and process equipment
- Hydraulic and utility systems
- Test equipment
- Industrial fluid handling systems
Selection & Ordering Information
To specify the required Hex Nipple, provide:
- Thread type at each end
- Thread size at each end
- Equal or reducing configuration
- Material
- Required working pressure
- Operating temperature
- Fluid or process medium
- Quantity
For mixed-thread configurations, specify the exact thread standard for both ends rather than nominal size alone.
Existing part numbers, drawings, BOMs or product references can also be provided for product matching and quotation review.
