By far, the most common scaffolding fixtures require a 21mm (7/16" BSW) socket.

Here at Thanet Tool Supplies we offer 8 variations of 1/2" drive Impact Sockets suitable for Scaffolding
Our range (below) starts with our highest selling socket IS12H21SCAF
ALL Scaffolder 21mm 1/2" drive Impact Sockets from Thanet Tool Supplies are supplied complete with a Ring and Pin.
No matter the 1/2" drive wrench you are using (Pin Indent or Ring & Pin) these sockets will fit and are ready to use.

Please note : BER3430 - 21mm x 52mm Trade Impact Socket IS NOT FULLY BROACHED and sometimes doesn't have enough depth to correctly fit fully over and undo fully wound tight fixtures (namely, those with too much excess thread protruding)