Long Product Mill

Long product is a common name for
• Reinforcement steel bars
• Shaped steel bar products such as rounds, flats, squares, and hexagon etc.,
• Sectional products such as angles (equal and unequal), channels, beams, tees, and special profiles etc., and
• Wire rods.

Mills which roll long products are known as long product mills. Based on the product being rolled these mills are called, merchant bar mill, bar and rod mill, light section mill, rebar mill, light merchant mill, special bar quality (SBQ) mill, and wire rod mill etc.

The product range of these mills usually consists of those shaped and sectional products whose cross-section is smaller than the cross section of the products rolled in medium and heavy section rolling mills. Wire rod mills produces steel wire rods of diameters 5 mm to 12.5 mm in coil form with the weight of the coil upto 2.5 tons. The qualities of steels being rolled in these mills can range from low carbon, mild steel, medium carbon, high carbon, and micro and low alloyed steels.
The design of the long product rolling mill is required to provide right solutions for the required performance requirements which include high speed production, microstructure qualities of the product, and shortest changeover time from one product to other product etc.
Large amount of flexibility is available in modern long products rolling mills. These mills are normally continuous mills consisting of three sets of rolling stands namely

• Roughing group of stands,
• Intermediate group of stands and
• Finishing group of stands. The input material for these mills is normally billet. A billet mill can be combined with the long product rolling mill through a roller hearth furnace in case the available input material is bloom. Similarly on the finishing mill side the mill can be combined with a wire rod mill so that wire rods can also be produced from the mill.

There is growing demands on the quality of the long products as well as on the flexibility and cost effectiveness of the long product mills. This has necessitated the development of new and innovative technologies and processes. Modern long product mills are high speed mills capable of rolling bars and light sections of special bar quality grades and engineering steels at high production rates, while keeping investments and operating costs at the reasonable levels.