The main components of the tubular scaffolding with couplers are the tubes and couplers, which will have a direct influence on the quality of the scaffolding system itself and its stability.

Tubes when recycled for many times will be more apt to be cursive and deformed. Many tubes when cut for many times will have many curves and bends at the connecting joints of the standing tubes and the surfaces of the ends of the steel tubes will be coarse and uneven, all of which will affect the stability and reliability of the standing tubes.

Steel tubes of 48*3.5mm which are available in the market, has a thinner wall than designed due to corrosion and disqualification even they are at the same scaffolidng prices, and the bearing capacity of the standing tubes will be reduced by 19%-27%. In addition, couplers with cracks, loose f the bolts and nuts or disqualification. When designing the scaffolding system at the same standard  of 3.5mm thickness of the tubes, the of couplers will also lag the bearing stability of the scaffolding frame.