The double coupler is a type of scaffolding coupler used to fix two scaffolding tubes at a right angle(90 degrees). It is called a scaffold double coupler, a double fixed coupler, a double coupler clamp, a right-angle coupler, a 90-degree coupler, a rigid coupler, etc.
Double couplers are classified into three types based on manufacturing method: pressed, drop-forged, and cast-iron.
The sizes of the double couplers are based on the outer diameters of the scaffold tubes they will fix, including 48.3mm, 60.3mm, 76mm, 89mm, etc.
The international safety standards for the double coupler are EN74, BS1139