Service Metal
150# Black Malleable Square Head Plugs
- SKU:
- SBSHP
- Availability:
- Usually Ships Same Day
- Weight:
- 0.00 LBS
Description
150# Black Malleable Iron Square Head Cored Plug
150# Black Malleable Iron Square Head Cored Plugs are designed to securely close female-threaded openings in piping systems while providing a removable termination point for maintenance, isolation, or future system changes.
Manufactured from durable malleable iron, these Class 150 plugs feature male NPT threads and a square head that provides convenient wrench engagement for installation and removal in industrial, commercial, plumbing, mechanical, gas, oil, and fire protection applications.
Product Highlights
- Square head cored plug for threaded piping systems
- Designed to close female-threaded pipe or fitting openings
- Male NPT threaded connection
- Square head provides convenient wrench engagement
- Removable closure for maintenance, isolation, or future access
- Durable black malleable iron construction
- Class 150 fitting
- Malleable castings conform to ASTM A197
- Malleable plugs conform to ASME B16.14
- NPT threads conform to ASME B1.20.1
- Class 150 fittings are UL Listed and FM Approved at 300 PSI
- Manufactured in an ISO-certified facility
- Country of origin: Thailand & China
Technical Specifications
| Product Type | Square Head Cored Plug |
|---|---|
| Material | Malleable Iron |
| Finish | Black |
| Pressure Class | 150# |
| Connection Type | Male NPT Threaded |
| Head Style | Square Head |
| Body Style | Cored |
| Primary Function | Threaded Opening Closure |
| Casting Standard | ASTM A197 |
| Plug Standard | ASME B16.14 |
| Thread Standard | ASME B1.20.1 |
| Listings / Approvals | UL Listed & FM Approved at 300 PSI |
| Manufacturing | ISO-Certified Facility |
| Country of Origin | Thailand & China |
Construction & Applications
Malleable Iron Construction
Manufactured from malleable iron castings conforming to ASTM A197 for dependable strength and durability in threaded piping installations.
Square Head Design
The square head provides flat wrenching surfaces that make the plug easier to tighten or remove during installation, inspection, and maintenance.
Male NPT Connection
The male threaded body installs into a compatible female NPT opening, with threads conforming to ASME B1.20.1.
Typical Uses
System Closure & Access
- Closing unused female-threaded openings
- Maintenance access points
- Temporary or permanent system isolation
- Future piping expansion points
Common Services
- Water piping
- Gas piping
- Oil piping
- Fire protection systems
- General mechanical piping
Need a Smaller Plug Size?
For sizes below 3/4", shop our selection of merchant steel square head plugs.
Ask Willy: Need Pipe Size Help?
Use our common pipe diameters and wall thickness chart to confirm sizing before ordering malleable iron fittings. You can also review the square head plug specification sheet and Certificate of Conformance below.
Standards & Approvals
ASTM A197
Malleable iron castings conform to ASTM A197.
ASME B16.14
Malleable bushings, plugs, and locknuts conform to ASME B16.14.
UL & FM
Class 150 fittings are UL Listed and FM Approved at 300 PSI.
Related Malleable Iron Standards
- Malleable fitting dimensions conform to ASME B16.3.
- Malleable bushings, plugs, and locknuts conform to ASME B16.14.
- Malleable unions conform to ASME B16.39.
- NPT threads on applicable fittings conform to ASME B1.20.1.
Need More Black Malleable Iron Fittings?
Shop our complete selection of 150# black malleable iron fittings, including plugs, caps, bushings, tees, elbows, couplings, unions, and other threaded fittings for industrial and commercial piping systems.
Frequently Asked Questions
What is a square head plug used for?
A square head plug is used to close a female-threaded opening in a pipe or fitting while maintaining the ability to remove the closure later if needed.
What type of connection does this plug use?
The plug uses a male NPT threaded connection that installs into a compatible female-threaded opening.
Why does the plug have a square head?
The square head provides flat surfaces for wrench engagement, making installation and removal easier.
What does “cored” mean?
Cored refers to the internal body construction of the plug rather than a completely solid body.
Is a plug the same as a cap?
No. A plug typically has male threads and installs inside a female-threaded opening, while a cap typically has female threads and installs over a male-threaded pipe end.
What material is this fitting made from?
The plug is manufactured from malleable iron castings conforming to ASTM A197.
What standard applies specifically to this plug?
The supplied product information states that malleable bushings, plugs, and locknuts conform to ASME B16.14.
What thread standard applies?
NPT threads conform to ASME B1.20.1.
Is this fitting UL Listed and FM Approved?
Yes. The supplied product information states that Class 150 fittings are UL Listed and FM Approved at 300 PSI.
Where can I find sizes below 3/4"?
For sizes below 3/4", use the Merchant Steel Square Head Plugs link above to view additional plug options.
Important Ordering & Installation Notes
- Confirm the required nominal thread size before ordering.
- This plug uses a male NPT threaded connection.
- Designed to close a compatible female-threaded opening.
- Malleable plugs conform to ASME B16.14 according to the supplied product information.
- NPT threads conform to ASME B1.20.1.
- Use the square head for wrench installation and removal.
- Use compatible thread sealant and accepted threaded piping installation practices.
- Verify system pressure, service, code, and approval requirements before installation.
- Refer to the specification sheet and Certificate of Conformance for additional product information.
