This is the Video Shows Workers from Wellmade Scaffold, China, are Welding Scaffold Stairs for Ringlock Scaffolding, Which is Parts of Access Scaffold Construction for the Moduar System.
You can Find From the Video that Workers are Welding Stair Tread Steps to Stair Stringer.
After Welding, Staircases are going to hot-dip galvanized.
Check the Welding Quality and Process in The China Scaffolding Factory.