The Faithfull High speed steel bi-metal hacksaw blades, virtually unbreakable in normal use. These blades give outstanding performance and are wear resistant. Suitable for most materials, such as aluminium, copper, brass, steel and cast iron. Available in either 18tpi or 24tpi and supplied two on a card. These Faithfull Hacksaw Blades have ideal toothing for most materials, IE, aluminium, copper, brass, steel and cast iron. Supplied as a carded 2 pack. Specification Size: 300mm (12in). TPI: 24.