Abstract: A clamping apparatus for use in assembling a picture frame as described herein comprises an anchoring corner block and a plurality of secondary corner blocks and a flexible cable. The cable has one end secured in the anchoring corner block and extends through the secondary corner blocks so that its other end may be releasably secured to the anchoring corner block. When the corner blocks are located in a position supporting an assembled set of picture frame members arranged in the required configuration a clamping load may be applied thereto by the corner blocks by applying a tensile load to the flexible cable. The various corner blocks are adapted to support the flexible cable in one or other of several predetermined planes selected to provide support for the particular frame moulding configuration which has to be clamped.