The world's standard theatrical lighting c clamp, the Mega-Clamp, is created from high tensile, aircraft grade, extruded aluminum. The Mega-Clamp's 600 pound design load is twice as strong as most cast iron clamps. In 1993, the Mega-Clamp was introduced to the industry. Microgrooves on the one-piece solid clamp body grip the pipe securely, preventing the fixture from rocking. With 600 lbs. of spring load when compressed, the Belleville spring washer keeps the fixture from drifting after small pan adjustments are made. Usually a wrench is not needed to tighten the pan bolt after minor adjustments. The Mega-Clamp fits from 1” pipe to 2” pipe (1-1/4” OD tube to 2.5” OD tube).