An alloy is a metal that has been made by combining two or more metals together to produce a final product which has more desirable properties than the individual elements from which it was made. Brass is an example of an alloy made by combining copper and zinc and is used to make the joints of some drain and chimney rods.
Chimney
A chimney is a vertical channel or pipe which conducts smoke and combustion gases up from a fire or furnace and typically through the roof of a building.
Creosote and tar
The thick brown oily substance that forms on the inside of a chimney consists of creosote and tar, which are by-products of burning wood and fossilised fuels.
This build-up reduces the efficiency of the boiler or stove and is a potential fire hazard.
Drain
A drain is a pipe designed to take waste water or sewage away from a building.
Female joint
With reference to drain and chimney rod joints, the female joint is the one with internal threads that the external (male) threads locate into.
Flue
A flue is a fireproof pipe in a chimney or connected directly to a boiler or stove, through which smoke, gas, or fumes ascend.
Flue liners are generally made of clay, terracotta or stainless steel and may be round, square or rectangular in shape.
High tensile carbon steel
High tensile carbon steel is steel which has carbon as the main alloying element. Carbon steel is stronger than non carbon steel (mild steel) but is more brittle.
Carbon steels are typically used in the manufacture of knives, saw blades, drill bits etc. where high strength and wear resistance is important but they can also be used in the making of steel drain rods.
Male joint
When referring to joints or fasteners on a drain or chimney rod, the male is the joint with external threads which are inserted into the corresponding internal (female) threads..
Oil tempered
Oil tempering involves heating the metal, then cooling it in oil.
Oil tempering will decrease the hardness and brittleness of the metal and at the same time increase its toughness. By controlling the rate at which the metal is cooled, it’s possible to alter the final balance between the hardness and toughness of the metal. This makes it possible to make a steel drain rod that is both strong and yet flexible.
Polypropylene
Polypropylene is a type of plastic and can be manufactured to be flexible or rigid.
It is used to make containers for yoghurt, margarine and take-out meals, as well as medicine bottles, bottle caps, and some household items.
Strength and flexibility makes polypropylene an ideal material for drain and chimney rods.
Rodding
Rodding is the act of using a drain rod or chimney rod. It is usual to use a push and pull motion to ease the progress of the rod.
Rusting
Rusting is a form of corrosion undergone by metals that contain iron. It occurs when such metals are left unprotected in the presence of oxygen and moisture in the atmosphere.
Brass is not subject to rust and is therefore the preferred choice for drain rod and chimney rod joints.
Spring steel
Spring steel is an alloy containing carbon and steel. Spring steel is a medium carbon steel with a high strength yet flexible.
This allows objects made of spring steel to return to their original shape despite significant bending or twisting. This property is utilised by coil spring drain rods.
Zinc plating
Zinc plating involves the electrolytic application of zinc by immersing clean steel parts in a zinc salt solution and applying an electric current.
This process applies a layer of pure zinc to the surface of the steel. Zinc plating imparts greater corrosion resistance to steel but is not as rust resistant as brass which is why brass is still regarded as the best material for a drain or chimney rod joint.