What is a Rolling Mill?
In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness and to make the thickness uniform. The concept is similar to the rolling of dough. Rolling is classified according to the temperature of the metal rolled. If the temperature of the metal is above its recrystallization temperature, then the process is known as hot rolling. If the temperature of the metal is below its recrystallization temperature, the process is known as cold rolling.
In terms of usage, hot rolling processes more tonnage than any other manufacturing process, and cold rolling processes the most tonnage out of all cold working processes. Roll stands, holding pairs of rolls, are grouped together into rolling mills that can quickly process metal, typically steel, into products such as structural steel (I-beams, angle stock, channel stock, and so on), bar stock, and rails. Most steel mills have rolling mill divisions that convert the semi-finished casting products into finished products.
There are many types of rolling processes, including ring rolling, roll bending, roll forming, profile rolling, and controlled rolling.
Interestingly, the invention of the rolling mill in Europe may be attributed to Leonardo da Vinci in his drawings. The earliest rolling mills in crude form but the same basic principles were found in Middle East and South Asia as early as 600 BCE. Earliest rolling mills were slitting mills, which were introduced from what is now Belgium to England in 1590. These passed flat bars between rolls to form a plate of iron, which was then passed between grooved rolls (slitters) to produce rods of iron.
Perhaps your company is expanding their operations and a rolling mill of this type is the perfect fit for you, whether it is steel guard rails, automobile parts, either new or aftermarket, incorporating a rolling mill into your operation will set you apart from other supply houses. Having the ability to handle the entire process from need to finish product will make you a leader in your specific field.
What Does An Upset Forging Machine Do?
Upset Forging is a manufacturing process whereby solid rod or bar stock (tubing can also be used) is placed into an Upset Forging Machine, commonly known as an upsetter. Upset Forging is also known as either Hot Heading or as Cold Heading.
Rod or bar stock is clamped by a set of Open or Split dies one side of which is operated through the use of gripping toggles and cams which are capable of withstanding enormous gripping pressures. These toggles are interlaced and supported both in the grip slide and bed-frame which provides uniform bearing pressures. The toggles are usually the full height of the dies to support the grip dies from top to bottom.
While Clamping Force is being applied, the dies close exerting the full gripping pressure which holds the blank in place during the Forging Process. A forging ram with a series of heading tools impacts the end of the rod or bar stock and either reduces the diameter, pierces the part, or increases the size by gathering material and Upset Forging it into a particular shape. This process takes place in between one and five hits. Each time the part is forged, the dies open and the part is moved down to the next position where the dies again close to grip the part. Each new position is forged with a different heading tool which gradually forms the part until the rod or bar end reaches the desired shape.
Upset Forging Machines or Upsetters are ideal for forging longer parts where only the end of a rod or bar blank needs to be forged. In some cases, where both ends need to be forged, the rod or bar can be turned around and re-fed into the upsetter.
This process can be applied on either hot or cold material.
Although upsetters are generally designed with horizontal clamping where one of the two dies moves side to side, some are designed with vertical clamping where one of the two dies moves up and down as opposed to side to side.
Material to be forged generally ranges from less than 1″ to up to 12″ in diameter. On the smaller machines, parts can be hand-fed. In some cases, magazine or automatic tong feeding systems are used for the feeding of part banks into the upsetter prior to the forging process.