Requirement of scaffold screw jack in coupler scaffoldings
For coupler scaffolding system, the external diameter of adjustable scaffold screw jack shall be no less than 36mm, and its diameter and distance between bolts shall comply with existing national regulations and requirements.
Bolt braces of adjustable screw jack shall be fastened to bracing plate by welding process with a welding height no less than 6mm; the screwing length of bolt rods and its nuts of adjustable screw jack shall be no less than the same length of 5 knots and the thickness of bolts shall be no less than 30mm. In addition, the designed anti-pressure working load value of adjustable screw jack shall be no less than 40 KN and its bracing plates shall be no less than 5mm in thickness.
On the other hand, when bolts are screwed up at a force of 65N/M, couplers in the scaffolding system shall be strong enough without any crack or chasm.