C-shaped clamp for quick-mounting lights to pipes and trusses. Opening widths 25–75 mm, load capacity up to 50 kg, with standard 16 mm or 28 mm pins.
Technical Details
Standard C-clamps for film sets have opening widths between 25mm and 75mm with a clamping force of 500-2000N. The threaded spindle uses an M8 or M10 thread, and the pressure plate typically measures 20x30mm. Professional versions made of forged steel can hold up to 50kg, while aluminum versions can hold up to 25kg. The spigot has standardized diameters of 16mm (5/8") or 28mm (1 1/8"). Baby C-clamps for smaller fixtures use 16mm spigots, while senior versions utilize the 28mm standard. Special variants with a quick-release mechanism (Speed-C-Clamp) reduce assembly time from 30 to 8 seconds.
History & Development
Theater technicians developed the first C-clamps around 1922 for stage lighting on Broadway. Hollywood adopted the system in 1935 when Hal Roach Studios first used C-clamps for studio lamps. Matthews Studio Equipment standardized the dimensions and threads for the US film industry in 1947. The introduction of aluminum alloys in 1963 reduced weight by 40% while maintaining stability. Modern CNC manufacturing since the 1990s allows for tolerances under 0.1mm for perfect fit accuracy.
Practical Use in Film
On "Blade Runner 2049" (2017), DoP Roger Deakins used over 200 C-clamps daily for practical lights on pipes and scaffolding of the futuristic sets. Standard workflow: mount C-clamp to truss, attach fixture, run cable – setup takes under a minute. Advantage: tool-free adjustment of light direction by loosening the wingnut. Disadvantage: vibrations with heavy fixtures over 30kg, requiring additional safety cables. In tight locations, mini C-clamps (opening 15mm) often replace larger solutions.
Comparison & Alternatives
Compared to pipe clamps, C-clamps offer faster tool-free mounting but have lower load capacity. Super clamps with larger openings (up to 55mm) are replacing C-clamps for thick pipes. Magnetic mounts replace them on steel structures when damage must be avoided. Suction cups are used on smooth surfaces like glass or car paint. Modern Cardellini clamps combine C-clamp functionality with adjustable jaws for irregular objects, achieving 30% higher holding force.