become an apprentice, one must be at least 18 years old and have a high school diploma or GED. Attending a trade or technical school combined with employer-provided training can accelerate the learning curve. According to U. S. Census Bureau data of 2012, boilermakers are the most male "saturated" job in the USA, having a share of 99.8 % males and 0.2 % females. R Stamp Welding Boiler repair in the United States is governed by the National Board of Boiler and Pressure Vessel Inspectors and the American Society of Mechanical Engineers (ASME) under a classification called R Stamp Welding. In order to perform R Stamp welds and repairs, boilermakers are tested and certified in the quality of their weld joints through a rigorous testing procedure. R stamps are issued to companies that have existing ASME code stamps issued for construction and whose quality control system covers repairs or follow the guidelines set up by ASME to obtain an R stamp. Welders identify their welds by stamping their identifying welder number adjacent to their completed weld with a set of steel stencils. Power Piping Welding, fitting, and installing the tubes and accessories that attach to the boiler can also be performed by boilermakers, and is governed by the same organizations as R Stamp Welding. This certification is called Power Piping and is governed by ASME Code section B31.1. Trade unions United States and Canada The International Brotherhood of Boilermakers, Iron Ship Builders, Blacksmiths, Forgers and Helpers is a labor union for boilermakers in Canada and the United States. UK In the UK, boilermakers traditionally joined the Boilermakers Society which merged with the General and Municipal Workers' Union (GMWU), then an unskilled union, to form the modern GMB which still maintains a "craft section" largely for boilermakers. Notable boilermakers and former boilermakers Omar Bradley - first Chairman of the Joint Chiefs of Staff Richard Carroll - American politician Billy Connolly - Scottish comedian Dave Charnley - boxer Fred Cornish - rugby player Horace Elgin Dodge - Dodge Motors founder John Francis Dodge - Dodge Motors founder Arthur Dooley - artist John A. Duffy - American Roman Catholic bishop Todd Graves - fast food entrepreneur John Hill - trade unionist Ted Hill - British politician James J. Jeffries (The Boilermaker) - American champion heavyweight boxer John MacDougall - British politician Duncan McNeil - British politician David Morehouse - CEO of the Pittsburgh