What Is A Scaffolding Coupler Used For? Scaffolding coupler is used to fix horizontal components such as scaffold transom, scaffold ledger, scaffolding plank in the vertical scaffolding tube to form a stable scaffolding system, so that workers can walk, construct and transport materials safely and stably on the scaffolding platform. A completed scaffolding system requires a variety of different types of scaffolding couplers. Next, I will introduce to you what specific functions different scaffolding couplers have?