Gi back nut

is a type of nut commonly used in plumbing fittings. Here’s what it typically refers to:

1. Material: “GI” stands for galvanized iron. Galvanized iron is iron or steel that has been coated with a layer of zinc to protect it from corrosion. This makes it suitable for use in plumbing applications, particularly where exposure to moisture is a concern.
2. Back Nut: A back nut, also known as a lock nut or jam nut, is a type of nut with a lower profile compared to standard nuts. It is tightened against another nut or fitting to lock it in place, preventing it from loosening due to vibration, thermal expansion, or other factors. In plumbing fittings, back nuts are commonly used to secure components such as valves, faucets, or pipe connectors.