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Internet # 100131775

Model # 521-403HN

Store SKU # 103772

1/2 in. Black Malleable Iron Cap Fitting

$2.38
  • Applications include oil, gas, LP gasses and decorative projects
  • UL and FM listings certify fitting meets top industry standards
  • Fittings connect with all NPT nipples and pipe of matching size
  • View More Details

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Product Details

About This Product

Southland offers one of the most extensive selections of black and galvanized malleable iron fittings in the industry. Our malleable fittings are available in 13 different diameters ranging from 1/8 in. up to 6 in. and each fitting is produced to exact industry specifications. All of our malleable iron fittings undergo rigorous testing to meet the quality standards you've come to expect from our B&K product lines.

Highlights

  • Our black malleable iron fittings are leak proof tested and threads are precisely machine tooled for easy connections to natural gas, propane, oil and air applications
  • Threads meet ANSI/ASME B1, 20.1 specification and 150 class ANSI/ASME B 16.3 dimensions
  • 150 class malleable iron pipe
  • 100% quality inspected and industry certified
  • Cap fitting closes off one end of malleable pipe
  • Malleable iron fittings and pipe are used in a multitude of DIY applications creating an industrial look for any home
  • Note: product may vary by store
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Product Information

Internet # 100131775

Model # 521-403HN

Store SKU # 103772

Additional Resources

Shop All Southland

Specifications

Dimensions

Fitting 1 size

1/2"

Fitting Size Dimensions

1/2"

Product Depth (in.)

1.5 in

Single Fitting Size

1/2"

Details

Application

Air, Natural Gas, Non-Potable Water, Oil

Color Family

Black

Compatible Pipe Material

Steel

Connection

FIP

Connection 1

FIP

Connectivity

Threaded

Features

Threaded

Fitting or Connector Type

Cap

Fitting/ Connector Collection

Black

Material

Iron

Maximum working pressure (psi)

300

Maximum Working Temperature (F)

350

Pack Size

1

Pipe or Fitting Product Type

Fittings & Connectors

Returnable

90-Day

Warranty / Certifications

Manufacturer Warranty

1 year

Questions & Answers

Is it safe to apply heat to this? I’m using it for a special project.
BySep 27, 2024
1 Answer | 
Answer This Question

Hello, this cap is made of malleable iron and has a maximum working temperature of 350-degrees Fahrenheit. We hope this helps with your project.

By|Sep 29, 2024


    Can this be welded? I am trying to make use of pipe and caps for the bottom of a workbench that needs to be easily broken down
    ByJun 12, 2023
    1 Answer | 
    Answer This Question

    Hello, this fitting is designed to thread onto black steel plumbing threaded pipe labeled as 1/2-in diameter. We recommend checking local codes for what is recommended for any application where threading is not feasible to ensure all aspects of your project are accounted for. We hope this helps with your project.

    By|Jun 12, 2023


      How do I know if this cap will fit? For plumbing purposes and it says on the water handle 150wsp/600 WOG
      ByApr 27, 2018
      1 Answer | 
      Answer This Question

      Hi Ali, this cap will fit 1/2in diameter black pipe.

      By|May 6, 2023


        can it be used outside?
        ByJul 27, 2017
        1 Answer | 
        Answer This Question

        Yes, this can be used outside.

        By|May 4, 2023

          (1)

          How is this threaded? Is it righty tighty / lefty loosey threaded or opposite? It is in a wood burning fireplace plumbed for gas also. The pipe and cap was installed almost 20 years ago and the fireplace has been wood burning all of that time. Considering installing natural gas logs now and need information on removing the cap to hook up to the logs.
          ByOct 9, 2015
          1 Answer | 
          Answer This Question

          Use two pipe wrenches, one to hold the pipe and one to remove the cap. Caps are generally righty tighty / lefty loosey. If pipe needs replacing you can remove that and replace it with a new nipple or pipe, threaded on both ends.

          By|Jan 4, 2026

            (2)

            Viewing 1-5 of 5

            Customer Reviews

            4.7 out of 5

            • 4.7 out of 249 reviews
            • 82% recommend this product
            Filter by:
            Showing 1-10 of 249 reviews
            Great for sealing a gas pipe that is no longer in use or as a cap for a dirt trap for a gas fixture. I used it to complete a dirt trap for a natural gas heater install. Traps for gas lines help keep dirt and debris from finding their way to you gas appliances which can cause clogs.
            by
            • Verified Purchase
            Perfect ?? very happy
            by
            • Verified Purchase
            I used this cap as part of connecting propane to a wall heater at my cabin. The machining was good and I had no issues with the several fitting I purchased to make my connection. A little pipe tape and no leaks on the first try.
            by
            • Verified Purchase
            Great cover or cap when in a pinch waiting for your appliance to be delivered A+
            Great cap for capping a stove gas line while waiting for it to be delivered
            by
            • Verified Purchase
            • Recommended
            It did not fit properly and I needed something to completely seal. Was told this would work to se...
            It did not fit properly and I needed something to completely seal. Was told this would work to seal off gas line for a dryer. Had to purchase a different product.
            by
            • Verified Purchase
            2 found this review helpful
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            Showing 1-10 of 249 reviews

            Compare Key Features

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            Product Snapshot

            Ideal for DIYers creating industrial looks with easy, leak-proof connections for gas, oil, and air applications.
            Ideal for DIYers creating industrial looks with easy, leak-proof connections for air, gas, and water piping.
            Ideal for DIY enthusiasts creating industrial-look projects with durable, 90° elbow fitting for gas, oil, and air applications.

            Diameter Compatibility

            1/8 in. to 6 in.
            1/8 in. to 6 in.
            3/4 in.

            Pressure Rating

            300 PSI
            300 PSI
            300 PSI

            Temperature Range

            Up to 350°F
            Up to 350°F
            Up to 350°F

            Corrosion Resistance

            Leak-proof Design