Scaffold tube of construction scaffolding and scaffolding element

The invention relates to a scaffolding tube (10) of scaffolding, with a tube axis (A) extending from a first axial end of the tube (12) to an opposite second axial end of the tube (14), provided one at the first axial end of the tube (12) receiving portion ( 16) and one (at the second axial end of the tube 14) provided for insertion section (18), which has a relative to the receiving portion (16) of reduced cross-section and ends with a radial shoulder (22) having a (the insertion portion 18) directed supporting surface (24) forms, wherein the inner diameter (d The receiving portion (16) has at the first axial end of the tube (12) has exactly one interrupted in the circumferential direction or circumferential positioning groove (26) on which the inner diameter (d Alternatively or additionally, a tube wall (34) of the scaffolding tube (10) at the first axial end of the tube (12) has a maximum wall thickness (s