UNP Channel Iron is part of steel construction, usually used for ladder structures, joists and car body construction. Unp iron can also be used for bracing in heavy steel construction either in heavy steel buildings or steel bridge buildings. Its use is almost the same as WF, except for columns that are rarely used because they are relatively prone to bending. Other terms: U channel, U-channel, U profile. UNP Iron of all sizes. This iron material is in the form of a U profile and is often called UNP, this material is widely used for civil and machine construction. This material has quite a lot of size variations so that we can easily adjust our needs.