This unique clamp is specially designed for closing gaps between floorboards before securing them in position. Extremely robust and compact, the clamps are standard equipment for professional flooring contractors, and they are designed to provide a long and reliable service life. The smooth operating bevel gears are fully enclosed in a solid grey iron casing for protection against dust and dirt. Features include strong spring loaded malleable iron cams, a high quality steel main screw and drop handle, and easy portability. Used in pairs, these clamps are easy to operate. When they are pushed down onto the joist, the spring loaded cams adjust automatically to create a positive grip on any joist between 38mm and 89mm (11/2 to 31/2) inches wide. The handle is then rotated to wind the shoe out against the floorboard until it is pushed fully home against the adjoining board and nailed before releasing the clamp.