Mild steel is the most common form of steel because its price is relatively low whilst it provides material properties that are acceptable for many applications. This steel usually contains less than 0.25% of carbon and insignificant amounts of alloying elements.
The material exhibits good weldability properties and is used in most general fabrication and structural steel applications.
In general we talk of two types of mild steel – bright and black:
- Bright mild steel as its name suggests is shiny to look at with a clean and slightly oiled finish.
- Black mild steel has a rougher, scaled finish that is dry to the touch.
High Yield Steels
High yield steel is another low carbon steel also typically containing less than 0.25% of carbon but the steel strength is increased through the addition of manganese and/or vanadium. This type of steel can also be further enhanced through small additions of molybdenum, niobium and titanium. This material again exhibits good weldability properties and is used in more demanding structural applications.
Carbon steels which can successfully undergo heat-treatment have a carbon content in the range of 0.30-1.70%. This type of steel is generally very strong with high levels of wear resistance. The steel is often used for hot forging/pressing components such as hand tools. Material in the higher band of carbon is also used for making high strength wires for applications such as spring steel.
Boron steel is a grade of steel, which can be processed at high temperatures by heating it in a furnace and pressing whilst still hot, using a cooled tool. The rapid cooling rate transforms the microstructure to form a very hard, tough and durable steel. This type of steel is used to form wear parts and for other applications where exceptional strength and wearability properties are required.
Engineering steels, also known as Special Bar Quality steels, represents a wide variety of higher-quality carbon alloy and free cutting bars that are used in the forging, machining and cold-drawing industries for the production of automotive parts, hand tools, electric motor shafts and valves. These steels generally contain higher alloy content than the commodity grades and are produced with more precise dimensions and chemistry.