These plugs are designed to seal and close off the ends of pipe runs or seal fitting ports.
The brass fittings are for above-the-waterline use only. 1/8" and 1/4"dia. plugs are offered in both brass and bronze. Due to the difference in nobility between brass and bronze, which can result in galvanic corrosion (and a failure of the fitting), we recommend that you not use these alloys together in saltwater environments.
To avoid this potentially hazardous situation, make sure you are not setting up the conditions for galvanic corrosion by connecting dissimilar brass fittings to bronze fittings. Generally, you can tell them apart just by looking at them. Bronze fittings have an outer surface that is rough in feel and appearance, almost like it’s covered with sand. That’s because bronze fittings are sand cast, and then machined.
Square Head Plugs
These machined brass or sand cast bronze fittings feature a square head and standard male pipe threads. Threads are tapered "NPT", which stands for "National Pipe Thread."