Service Metal
Stainless Steel 150# NPT Square Head Plug
- SKU:
- SSPSHP
- Availability:
- Usually Ships Same Day
- Weight:
- 0.00 LBS
Description
Stainless Steel 150# NPT Square Head Plug
Stainless Steel 150# NPT Square Head Plugs provide a threaded closure for female NPT ports and piping connections. Available in both 304 and 316 stainless steel, these plugs feature a male NPT connection and a square head for wrench engagement during installation and removal.
The SSP4SHP series is manufactured from 304 stainless steel, while the SSP6SHP series is manufactured from 316 stainless steel. Both material grades are available in nominal sizes from 1/8" through 4".
Product Highlights
- Square head threaded pipe plug
- Available in 304 or 316 stainless steel
- 150 lb pressure class
- Male NPT threaded connection
- SP114 pattern
- Designed to close compatible female NPT connections
- Square head provides wrench engagement
- Corrosion-resistant stainless steel construction
- Available in nominal sizes from 1/8" through 4"
- All listed sizes available in both 304 and 316 stainless steel
- Manufactured by Service Metal
Technical Specifications
| Manufacturer | Service Metal |
|---|---|
| Product Type | Square Head Plug |
| Material Options | 304 Stainless Steel or 316 Stainless Steel |
| Pressure Class | 150 lb |
| Connection Type | Male NPT Threaded |
| Head Style | Square Head |
| Pattern | SP114 Pattern |
| Available Sizes | 1/8", 1/4", 3/8", 1/2", 3/4", 1", 1-1/4", 1-1/2", 2", 2-1/2", 3" and 4" |
| 304 SS Series | SSP4SHP |
| 316 SS Series | SSP6SHP |
Choose 304 or 316 Stainless Steel
304 Stainless Steel
The SSP4SHP series is manufactured from 304 stainless steel and provides corrosion resistance and durability for industrial, commercial, mechanical, and general threaded piping applications where 304 stainless steel is compatible with the service conditions.
316 Stainless Steel
The SSP6SHP series provides the same square-head plug configuration in 316 stainless steel. Select 316 stainless steel when that material grade is specified or required for the piping system or application.
Square Head Plug Configuration
Male NPT Connection
- Male NPT threaded connection
- Threads into compatible female NPT ports
- Provides a removable threaded closure
- No welding required for installation
- Available across a broad range of nominal pipe sizes
Square Head
- Square head provides wrench flats
- Helps provide controlled installation and removal
- Useful for maintenance-access applications
- Compact plug configuration
- Suitable for threaded piping and equipment ports
Available Sizes & Materials
Every nominal pipe size in this listing is available in both 304 stainless steel and 316 stainless steel:
- 1/8" — 304 SS or 316 SS
- 1/4" — 304 SS or 316 SS
- 3/8" — 304 SS or 316 SS
- 1/2" — 304 SS or 316 SS
- 3/4" — 304 SS or 316 SS
- 1" — 304 SS or 316 SS
- 1-1/4" — 304 SS or 316 SS
- 1-1/2" — 304 SS or 316 SS
- 2" — 304 SS or 316 SS
- 2-1/2" — 304 SS or 316 SS
- 3" — 304 SS or 316 SS
- 4" — 304 SS or 316 SS
Performance Features
150 lb Class
These square head plugs are identified as 150 lb class stainless steel threaded fittings.
NPT Threaded
The male NPT connection allows the plug to close a compatible female threaded fitting, valve, equipment port, or piping connection.
Two Stainless Grades
Select 304 or 316 stainless steel according to the piping specification and material requirements of the application.
Common Applications
Industrial & Process Piping
- Industrial piping systems
- Process piping
- Utility piping
- Equipment ports
- Valve and manifold connections
- Maintenance and repair installations
Commercial & Mechanical Piping
- Commercial mechanical systems
- Stainless steel piping assemblies
- Equipment rooms
- Temporary or permanent port closures
- General threaded piping
- Applications requiring stainless steel fittings
Selecting the Correct Square Head Plug
Select the plug according to the nominal pipe size and stainless steel grade required by the system. SSP4SHP-series plugs are 304 stainless steel, while SSP6SHP-series plugs are 316 stainless steel.
These fittings have a male NPT threaded connection and are intended to close compatible female NPT ports or fittings. Confirm the nominal size, thread type, and required stainless steel grade before ordering.
Ask Willy: Need Pipe Size Help?
Use our common pipe diameters and wall thickness chart to confirm sizing before ordering 150# stainless steel threaded square head plugs. You can also review the product specification sheet and Certificate of Conformance below.
Product Documentation
Product Specification Sheet
Review the specification sheet for dimensional and product-specific information on the 150# stainless steel threaded square head plug.
Pipe Size Chart
Use the common pipe diameters and wall thickness chart to help confirm compatible pipe sizing before ordering.
Certificate of Conformance
Certificate of Conformance documentation is available through the linked PDF.
Installation & Selection Guidance
- Confirm the required nominal pipe size before ordering.
- Select either 304 or 316 stainless steel according to the piping specification.
- Verify that a male NPT threaded plug is required.
- Confirm stainless steel compatibility with the intended service.
- Use thread sealant suitable for the piping material and conveyed media.
- Avoid cross-threading during installation.
- Use the square head for controlled wrench engagement.
- Use appropriate practices to minimize stainless steel thread galling.
- Do not over-tighten threaded stainless steel fittings.
- Confirm pressure and temperature requirements for the complete piping system.
- Inspect completed connections for leakage before placing the system into service.
- Follow applicable piping codes and project specifications.
Need Help Selecting Stainless Steel Fittings?
Our industrial PVF specialists can help review your pipe size, stainless steel grade, connection requirements, and application before you order.
Frequently Asked Questions
What is a square head plug used for?
A square head plug is used to close a compatible female NPT threaded opening in a pipe fitting, valve, manifold, or piece of equipment.
Are these plugs available in both 304 and 316 stainless steel?
Yes. Every nominal size in this listing is available in both 304 and 316 stainless steel.
What is the difference between SSP4SHP and SSP6SHP?
The SSP4SHP series is manufactured from 304 stainless steel, while the SSP6SHP series is manufactured from 316 stainless steel.
What connection type does this plug use?
These square head plugs use a male NPT threaded connection.
Why does the plug have a square head?
The square head provides wrench flats that can assist with controlled installation and removal.
What pressure class are these fittings?
These stainless steel square head plugs are identified as 150 lb class fittings.
What sizes are available?
Available nominal sizes are 1/8", 1/4", 3/8", 1/2", 3/4", 1", 1-1/4", 1-1/2", 2", 2-1/2", 3", and 4".
How do I select the correct variant?
Select the nominal size that matches the female NPT opening being plugged, then select either 304 or 316 stainless steel according to the piping specification.
Important Ordering Notes
- This listing is for stainless steel square head plugs.
- SSP4SHP-series SKUs are 304 stainless steel.
- SSP6SHP-series SKUs are 316 stainless steel.
- Fittings are 150 lb class.
- Connections are male NPT threaded.
- Product is identified as an SP114 pattern fitting.
- Available nominal sizes range from 1/8" through 4".
- All listed sizes are available in both stainless steel grades.
- Select the correct nominal pipe size and stainless steel grade before ordering.
- Verify material compatibility with the intended application.
- Confirm system pressure, temperature, and material requirements before installation.
- Product dimensions and weight vary by selected size.
