NCCER/OSHA Scaffold SG Practice Test

The normal outside diameter (O.D.) of a tube in a tube and clamp scaffold is typically 1.9 inches. This specific diameter is standardized because it provides the necessary strength and stability needed for scaffolding applications, while also allowing for compatibility with clamps and other components that are designed to fit securely around this dimension.

Using the 1.9-inch diameter ensures that the scaffold can safely support the loads it is designed to carry, providing safety for workers and maintaining the integrity of the structure. Additionally, this standardization across the industry makes it easier for builders to specify materials, maintain inventory, and ensure that components are interchangeable.

Other diameters, such as 1.5 inches, 2.0 inches, or 2.5 inches, do not conform to the established standard for tube and clamp scaffolding, and using them could compromise the safety and stability of the scaffolding system.