Steel erection essentially consists of four main tasks:Establishing that the foundations are suitable and safe for an erection to commence.Lifting and placing components into position, generally using cranes but sometimes by jacking. To secure components in place, bolted connections will be made, but will not yet be fully tightened. Bracings may similarly not be fully secured.Aligning the structure, principally by checking that column bases are lined, and level and columns are plumb. Packing in beam-to-column connections may need to be changed to allow column plumb to be adjusted.Bolting-up, which means completing all the bolted connections to secure and impart rigidity to the frame.