EN10255 is the harmonized European Standard for non-alloy steel tubes suitable for welding and threading. It has largely superseded the famous BS1387 specification.
Application: These pipes are the global "workhorse" for conveying low-pressure fluids like water, gas, and air.
Grades: They are categorized by wall thickness into Light (L), Medium (M), and Heavy (H) series. A "Heavy" class pipe has a thicker wall to withstand higher pressure or corrosive environments compared to a "Light" class pipe.