Malleable iron fittings are made from malleable cast iron. It’s important to note that while malleable iron (often referred to as “malleable steel” in some contexts) has good toughness, it is not suitable for forging. Malleable iron fittings are categorized based on the pipe material itself, whereas galvanized fittings are classified according to the surface treatment of the pipe.
Difference Between Malleable Iron and Galvanized Fittings
Malleable iron fittings are made of iron, which is prone to rust when exposed to air. This is especially relevant since our malleable iron fittings are widely used in fire protection systems and water supply projects—applications that often involve humid or damp environments. Therefore, a surface anti-corrosion treatment is essential.
The most common surface treatments for malleable iron fittings are hot-dip galvanizing and electro-galvanizing (also known as cold galvanizing).
- Hot-dip galvanizing involves immersing the fittings in molten zinc at a temperature of 700–800°C, creating a thick, durable zinc coating that adheres firmly to the surface.
- Cold galvanizing is an electroplating process where zinc from the anode is transferred and deposited onto the cathode—the surface of the iron fitting—resulting in a thin but uniform layer of protection.
Malleable iron fittings are also known as threaded pipe fittings, and in many cases, the term “galvanized fittings” refers to galvanized malleable iron fittings. However, it is important to distinguish between them: not all galvanized fittings are made from malleable iron. Some welded or other types of iron fittings may also be galvanized. Therefore, from a strict technical perspective, galvanized fittings are not necessarily malleable iron fittings.
