According to the bearing parts in the system, the scaffold working load can be defined as follows.

Scaffolding working load delivered by friction on the surface. The friction produced by the pressure between the joints will sustain the working load

from the transverse tubes and then pass it to the standing tubes, which can be well demonstrated by the couplers, which will produce the friction by

the positive pressure when fastening the bolts and nuts.

The one delivered by the welding gaps, which are widely adopted on the combining of the transverse tubes and the standing tubes, so do the frame

scaffoldings.

The one directly pass the working load on the inner scaffolds with transverse tubes on the top of the standing tubes.

The one passes the working load by the bridging and shearing of the pin braces, i.e. the vertical connection for the pin braces through the transverse

tubes to tie to the holes.