• Square socket pipe plugs are threaded devices designed to put a removable seal at the end of a pipe. They are installed and removed with a square-headed socket wrench, which fits into a recess in the plug. Square socket pipe plugs can be specified in a wide range of materials and dimensions.
  
  

Materials

• Square socket pipe plugs can be specified in steel, aluminum, brass, or malleable iron. They are usually specified to match the material of the pipe, to prevent bimetallic corrosion.
  
  

Length Standards

• These plugs are generally specified in long standard or short standard lengths. Long standard plugs are .03 inch longer than short standard plugs. For example, a 1/8-27 short standard plug has a maximum body length of .28 inch, while a 1/8-27 long standard plug has a maximum body length of .31 inch.
  
  

Diameter

• Standard diameters for square socket pipe plugs include 1/8, 1/4, 3/8, 1/2, 3/4 and one inch.
  
  

Socket Depth

• Depth of the square socket in the plug range may be specified at .197 inch (for 1/8-27 plugs), .16 inch (for 1/4-18 and 3/8-18 plugs) .19 inch (for 1/2-14 and 3/4-14 plugs) and .25 inch (for 1-11 1/2 plugs).