In metallurgy, the term skelp refers to pieces of iron or steel that may be forged into long, narrow strips. These can then be bent or made circular, by using tools and machines, such as welding equipment, bick irons, or furnaces equipped with various types of rollers. Skelp is typically used in the manufacture of various types of goods such as pipes, tubes, and gun barrels. It is sometimes spelled as scelp.
It is usually made from a piece of bar iron that has been selected due to its length and thickness. These precise dimensions generally depend on what the skelp will be used for. The distinctive feature of it is that its thickness and width are not very large, in proportion to its length. This is one of the reasons why skelp came to be known by its own particular name, and because its specific practical uses set it apart from other metallurgic materials.
In the old days of skelp manufacturing, iron would be heated in a coal fire and then hammered into shape. The iron could then also be bent using a jig or bick iron. Common contemporary welding methods for turning the material into pipe are arc welding and gas welding. In modern mass production, there are many different ways to produce skelp, two of which are the continuous process and the reversible process. These methods are generally used for hot rolling steel skelp.
In the continuous process, a steel slab is placed into a furnace to be reheated at an ideal temperature for rolling. The slab is fed into a series of roll stands, where the rollers — as their name implies — begin to roll the steel. This gives the slab a round shape, and reduces the thickness of the steel. Experts generally consider this to be a fast production method, however it is not economically practical because a lot of rolling stands and machinery is required. For this reason, the continuous technique is typically only used in mass production.
The reversible process uses one set of rolls, located in a furnace, as opposed to a series of stand rolls. In this method, the skelp is moved back and forth between the rolls. This movement continues until it acquires the desired shape. The reversible process is also used almost exclusively in mass production.
Skelp is often a term associated with gunsmithing, since gun barrels are sometimes made from the material. However, these gun barrels are generally thought to be of lesser quality, as they are typically unable to withstand the pressures generated by combustion. The Damascus method of gun barrel manufacturing refers to the hammering and forging of skelp, after which it is wrapped around a bick iron to form a gun barrel.