<P> The team's current primary logo was introduced in 1962 and is based on the flag originally designed by Pittsburgh's U.S. Steel and now owned by the American Iron and Steel Institute (AISI). Ironically, it was Robert Sexton, an employee out of the Pittsburgh office of Cleveland - based Republic Steel, that suggested the Steelers adopt the industry logo . It consists of the word "Steel" surrounded by three astroids (hypocycloids of four cusps). The original meanings behind the astroids were, "Steel lightens your work, brightens your leisure, and widens your world ." Later, the colors came to represent the ingredients used in the steel - making process: yellow for coal, orange for iron ore, and blue for scrap steel . While the formal Steelmark logo contains only the word "Steel," the team was given permission to add "ers" in 1963 after a petition against AISI . </P> <P> While the logo still resembles the original Steelmark logo, the team has made subtle changes over the years in order to own a trademark on the logo, most notably making the three astroids thicker in shape and changing the orange astroid to red . The Steelmark logo itself has actually been heavily redesigned since then, using two variants, one of which uses a more modern design and uses three shades of blue for the astroids while another one used concurrently has a strong resemblance to the recycling symbol . One alternate variation the team used in the 1980s--though rarely used today--combined the logo with the team's signature stencil - script typeface, replacing the regular "Steelers" typeface used with the team's longtime script logo . </P> <P> The Steelers are the only NFL team that puts its logo on only one side of the helmet (the right side). Longtime field and equipment manager Jack Hart was instructed to do this by Art Rooney as a test to see how the logo appeared on the gold helmets; however, its popularity led the team to leave it that way permanently . Since then, several college football teams such as Michigan State have followed the Steelers approach at one point or another and had their logo on only one side of the helmet . At the end of the 1962 season, they switched to black helmets for the 1962 Playoff Bowl to make it stand out more, and adopted the black helmets full time from the 1963 season onward . In 1977, the Steelers switched facemask colors from gray to black . </P> <P> Another feature of the helmet is that a player's uniform number appears on both the front and back (the Steelers are one of only two teams in the NFL to do so, with the other team being the New York Giants). Just like the Giants, the Steelers have the two digit helmet numbers located to the left and right of the center stripe on both the front and back of the helmets . Also just like the Giants, the Steelers have the one digit helmet number located on the center stripe on both the front and back of the helmets . The numbers traditionally do not appear on the front of the helmet during the exhibition season, and also do not appear on the front of the throwback helmets . </P>

Why is the steelers logo on one side
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