Structural steel fabricators uses shot blasting machine to clean structural steel prior to painting for long painting life. Construction industry uses shot blasting machine for powder coating of toasted steel bars, hot deep galvanizing of transmission and television towers. Roller conveyor type machines are used for this applications. Earth moving machine manufacturers uses shot blasting machine for cleaning and preparing surface of welded components. Blast cleaned surface gives longer paint life. Mechanical shot blasting has many advantages over pickling.