A cable clamp adapted for use in cable-stretching installations. The cable clamp includes stationary and swingable clamp assemblies where the swingable assembly is connected to the stationary assembly for swinging movement with respect thereto between clamping and unclamping positions. The stationary assembly is formed as a power cylinder for a piston guided for movement toward the swingable assembly and urging a lining which directly engages the cable toward a corresponding lining carried by the swingable assembly.