0.5 Gi back nut

a specific type of back nut used in plumbing fittings, with a nominal diameter of 0.5 inches, typically used with pipes or fittings of the same size.

Here’s what each part of the term means:

1. 0.5: This indicates the nominal size of the back nut, which is half an inch in diameter. This measurement corresponds to the size of the pipe or fitting it’s intended to be used with.
2. GI: This stands for “Galvanized Iron,” indicating the material the back nut is made from. Galvanized iron is iron or steel that has been coated with a layer of zinc to protect it from corrosion, making it suitable for use in plumbing applications.
3. Back nut: As previously described, a back nut is a type of nut used to secure components in plumbing fittings. It’s tightened against another fitting to lock it in place, preventing it from loosening due to vibration or movement.