Abstract: A connector for use in builder's scaffolding systems for connecting crossmembers to upright members where the upright members have sockets provided thereon and each of the sockets has an internal clamping face. The connector is coupled to one end of the crossmember. It has an upper and a lower limb spaced apart for receiving the socket therebetween. A generally trapezoidal opening having four sides, two of which are non-parallel, is provided in the two limbs. In engaging the connector, two of the four sides form first and second clamping sides. A wedge coupling member is received within the trapezoidal opening and mounted for clamping engagement with the internal clamping face of the socket and selected portions of the first and second clamping sides. The trapezoidal opening permits connection of the crossmember at a plurality of angles to the upright within the range permitted by the first and second clamping sides.