Scaffolding comes in various types, and each type has regulations specifying the wall thickness of the steel pipes. However, in practice, some flexibility is allowed depending on the actual situation. The most common types of scaffolding include coupler-type steel pipe scaffolding, bowl-type steel pipe scaffolding, disc-lock type steel pipe scaffolding, ring-lock type steel pipe scaffolding, and frame-type steel pipe scaffolding.
The standard for coupler-type steel pipe scaffolding is JGJ130-2011 “Safety Technical Specification for Coupler-Type Steel Pipe Scaffolding in Building Construction.” Section 3.1.2 stipulates that φ48.3*3.6 scaffolding steel pipes should be used; Table 8.1.8 specifies that the allowable deviation for the steel pipe wall thickness is ±0.36mm.
The standard for cup-lock steel pipe scaffolding is JGJ166-2016, “Safety Technical Specification for Cup-Lock Steel Pipe Scaffolding in Building Construction.” Section 3.3.1 stipulates that scaffolding steel pipes should preferably have a nominal size of φ48.3*3.5 mm, with an allowable deviation of ±0.5 mm for the outer diameter and a non-negative deviation for the wall thickness. The minimum wall thickness is specified to be no less than 3.0 mm.
The standard for disc-lock steel pipe scaffolding is JGJ231-2016, “Safety Technical Standard for Socket-Type Disc-Lock Scaffolding in Building Construction.” Section 3.0.1 stipulates that the scaffolding components, materials, and fabrication quality should comply with the current industry standard JG/T503, “Socket-Type Disc-Lock Steel Pipe Scaffolding Components.”
Currently, there are no industry or national standards for ringlock steel pipe scaffolding. Local standards exist primarily in regions where they are widely used. For example, in Beijing, the local standard is DB/T1871-2021, “Safety Technical Specification for Ringlock Steel Pipe Scaffolding in Building Construction.” Section 3.2.3 stipulates that the specifications for upright steel pipes should preferably be φ48.3*3.6mm, and for horizontal steel pipes, φ48.3*3.2mm. It also specifies that the allowable deviation for the outer diameter of uprights and horizontal pipes is ±0.5mm, and the allowable deviation for wall thickness is ±10%.
The specification for portal steel pipe scaffolding is JGJ/T128-2019, “Safety Technical Standard for Portal Steel Pipe Scaffolding in Building Construction.” Section 3.0.4 stipulates that scaffolding steel pipes with a specification of φ42*2.5mm are preferred, but scaffolding steel pipes with a diameter of φ48*3.5mm can also be used. The allowable deviations for the outer diameter, wall thickness, and shape of the scaffolding steel pipes should comply with the regulations.
Regarding the wall thickness of scaffolding steel pipes, the specifications require one aspect, but the actual site conditions must also be considered. The specifications are rather optimistic, but site conditions are often less so, and a significant portion of the scaffolding steel pipes do not meet the specifications. Taking coupler-type scaffolding steel pipes as an example, in my experience, only a few of the scaffolding steel pipes used had a wall thickness of 3.0mm. To ensure construction safety and to keep the project moving forward, I adopted a method of calculating the stress on scaffolding steel pipes with a wall thickness of 2.8mm, which served as the wall thickness control standard for on-site acceptance of the scaffolding steel pipes. Taking ringlock-type scaffolding steel pipe uprights as another example, in my experience, the scaffolding steel pipes used in the projects I’ve worked on generally had a wall thickness of less than 3mm. Again, to ensure construction safety and to keep the project moving forward, I adopted a method of calculating the stress on scaffolding steel pipes with a wall thickness of 2.5mm, which served as the wall thickness control standard for on-site acceptance of the scaffolding steel pipes. This necessitates the careful inspection of scaffolding steel pipe wall thickness using calipers during on-site acceptance. Scaffolding steel pipes with wall thicknesses that do not meet actual control standards must be rejected as substandard materials.
At this point, you should understand the meaning of “flexibility” I mentioned. This flexibility is mainly due to market factors in the scaffolding industry and the accountability system for scaffolding safety accidents. Market factors in the scaffolding industry refer to the fact that the industry is primarily rental-based, and many scaffolding manufacturers and rental companies neglect the quality of scaffolding steel pipes to control costs. The accountability system for scaffolding safety accidents means that after a safety accident, the construction company is usually held responsible; there are virtually no cases of scaffolding manufacturers and rental companies being held accountable for substandard steel pipe quality. This also leads to a lack of attention to the quality of scaffolding steel pipes by these companies.
The same approach applies to controlling wall thickness for other, less common types of scaffolding. On the one hand, relevant specifications are consulted; on the other hand, the actual situation is considered to find a reasonable wall thickness control value as the basis for calculations and on-site material acceptance.
Post time: Apr-16-2026