The document specifies the requirements for materials and design, and test procedures and methods, for couplers, loose spigots and base-plates used for connecting steel tubes of 48,3 mm outside diameter and of at least 3,2 mm nominal wall thickness at a minimum in the construction of working scaffolds and falsework required for the construction, maintenance, repair and demolition of buildings and structures. The requirements and test procedures specified are for the assessment of prototypes.