Apollo ball valves are are made from leaded red brass and semi-leaded red brass. I asked Conbraco, the manufacturer of Apollo valves, "What are the allow numbers for the metals in their valves?" The alloy numbers are for leaded red brass and semi-leaded red brass. Most "marine" hardware, including Groco valves, is manufactured from these alloys. The exception is hardware and fittings manufactured by Davey & Company, Ltd in England. They use gunmetal unless noted otherwise in their catalog. Gunmetal is composed of 85% copper, 5% tin, 5% lead and 5% zinc. Also known as C85555. The reason these allows are referred to as bronze is because there is no legal definition for bronze.
Leaded brass works very well in a marine environment. Most of IDUNA's seacocks were installed over 25 years ago and are still very serviceable. Brass, an allow of copper and zinc is not suitable for service in a marine environment. In a saltwater environment, the zinc in the brass becomes an anode and is leaches out as zinc ions. The action weakens the brass and it eventually fails.
More information about alloy numbers may be found at [www.anchorbronze.com
] . Properties of brass allows may be found at [www.azom.com
IDUNA seacocks are tradition plug valves with bases and are thru-bolted through the hull with three 1/4" silicon bronze flat head machine screws. Ball valves screwed on the end of a thru-hull are not seacocks. Proper seacocks have bases and are thru-bolted - ABYC standard. By-the-by, IDUNA's seacocks are fitted with grease cups and can be lubricated in place - [www.essexbrass.com
] . The grease cups are not cheap but IDUNA's seacocks always work and very seldom leak.
Tradition seacocks may be purchased from Spartan Marine - [spartanmarine.com
Davey & Company Ltd (importer) [www.rwrope.com