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Gages
Gages

Short Casing Thread Plug and Thread Ring Gages

To use short casing gages, the following steps are recommended:

  • Clean the threads of the casing and the gage with a suitable solvent and a brush. Remove any dirt, rust, grease, or burrs that may affect the accuracy of the measurement.
  • Apply a thin layer of thread compound or lubricant to the threads of the gage. This will reduce friction and wear, and prevent galling or seizing of the threads.
  • Insert the plug gage into the casing or the ring gage over the casing, and rotate it by hand until it engages with the threads. Do not use any tools or force to tighten the gage, as this may damage the threads or the gage.
  • Measure the standoff distance between the face of the gage and the face of the casing, using a calibrated depth micrometer or a feeler gauge. The standoff distance is the gap that indicates the degree of fit between the threads. Compare the measured standoff distance with the allowable range specified by API Spec 5B. If the standoff distance is within the range, the threads are acceptable. If the standoff distance is outside the range, the threads are either too tight or too loose, and may cause leakage or failure of the casing.
  • Remove the gage from the casing by rotating it in the opposite direction. Clean the threads of the gage and the casing again, and store the gage in a protective case.

Short casing thread plug and ring gages are used to inspect the threads and dimensions of casings, which are pipes that line the walls of a drilled well. Casings are essential for the stability and safety of the well, as well as the extraction of oil and gas. The American Petroleum Institute (API) has developed standards for the design, manufacture, and inspection of casings and their threads, known as API Spec 5B.


Short casing gages are one type of gage that conform to API Spec 5B. They have an 8-round thread with a coupling, which means they have 8 threads per inch, a 3/4 inch taper per foot, and a 60 degree thread angle. The gages are classified as either plug gages or ring gages, depending on whether they are used to check the internal or external threads of the casing.


Short casing gages are important tools for ensuring the quality and performance of casings and their threads. By following the proper procedures and standards, users can avoid potential problems and risks associated with casings and wells.


If you have any technical questions; our team of engineers has served on many different API gaging subcommittees with over 100 years of experience. We are here to assist you with any questions or special requirements you may have.


You can contact us at: 888-400-4243 with any questions or quoting you require or email your prints to quote@westportcorp.com.

Gages