Ruby Loftus Screwing a Breech Ring is a 1943 painting by the British painter Laura Knight depicting a young woman, Ruby Loftus (1921–2004), working at an industrial lathe as part of the British war effort in World War II. The painting was commissioned by the War Artists' Advisory Committee (WAAC), and is now part of the Imperial War Museum's art collection. The painting brought instant fame to Loftus, and has been likened to the American figure of "Rosie the Riveter".