|This article does not cite any references or sources. (November 2009)|
Terne is an alloy coating that was historically made of lead and tin used to cover steel, in the ratio of 20% tin and 80% lead. Currently, lead has been replaced with the metal zinc and is used in the ratio of 50% tin and 50% zinc. This alloy has a low melting point of approximately 360 degrees Fahrenheit.
Terne is used to coat sheet steel to inhibit corrosion. It is one of the cheapest alloys suitable for this, and the tin content is kept at a minimum while still adhering to a hot-dipped iron sheet, to minimize the cost.
Terne metal must be painted. If the paint is maintained, terne metal can last 90 years or more. Terne coated stainless steel (TCS) or copper is commonly used to replace terne metal roofs as either material will outlast terne metal. TCS or copper roofing can last 50 years or more unpainted.
Terne-coated steel is also known as terne-metal and often referred to as "tin" (see the Slate Roof Bible). Terne-coated steel can still be purchased at most roofing supply stores.
|This alloy-related article is a stub. You can help Wikipedia by expanding it.|