Abstract: The invention is concerned with a clamping device for clamping together a scaffolding pole and the flange of a construction member. The device comprises two body parts having arcuate seats, the two body parts being connected together at one end thereof for relative pivotal movement, and the device comprising clamping means to secure the body parts in clamping engagement with the scaffolding pole.The arcuate seats are spaced apart in the axial direction, and one body part comprises an integral extension portion, which extends generally parallel to the longitudinal axis, such that the arcuate seat on the other body part lies (in the axial direction) between the arcuate seat of said one body part and a flange-engaging surface of the extension portion. In this manner by tightening a single nut the clamping means may be operated to secure the clamping device to the scaffolding pole, and simultaneously clamp the flange between the extension portion and the scaffolding pole.