This plug style garboard drain assembly is cast brass threaded for 1/2” pipe plug. Flanges are drilled and countersunk for three #8 flat head mounting screws. There's also a plug with the dry seal thread pitch to ensure no water seepage. Unlike hollow plugs which are subject to cracking by the expansion of freezing water, this solid plug will withstand this pressure and remain watertight. These plugs are chemically resistant to all fuels, oils and battery acids found in typical boat bilges.
