HSAW Steel Pipe vs LSAW Steel Pipe: What's the Difference?
2026-01-09
HSAW Steel Pipe vs LSAW Steel Pipe: What's the Difference?
In large-diameter pipeline projects, HSAW steel pipes and LSAW steel pipes are two widely used solutions. Although both are manufactured using submerged arc welding technology, their forming methods, structural characteristics, and ideal applications differ significantly.
This article explains what is LSAW pipe, introduces hsaw pipes, and clearly answers what is the difference between LSAW and HSAW, helping engineers and buyers choose the right pipe for their projects.
What Is LSAW Pipe?
LSAW (Longitudinal Submerged Arc Welded) pipe is manufactured from steel plate rather than coil. During production, the plate is formed into a tubular shape using U-press and O-press forming methods. The two edges are then joined by submerged arc welding, creating a straight weld seam along the length of the pipe.
After welding, the pipe undergoes mechanical expansion, dimensional inspection, non-destructive testing, and end finishing. A critical factor in LSAW pipe production is the choice of welding filler material. To maintain balanced mechanical properties, the filler must closely match the base steel and avoid excessive overmatching.
With its uniform structure and excellent pressure resistance, LSAW pipe is well suited for applications that require high strength and reliability.
Key Features of LSAW Pipe
- Straight longitudinal weld seam with stable stress distribution
- High dimensional accuracy and consistent wall thickness
- Excellent resistance to internal pressure
- Strong tensile strength and overall toughness
- Commonly used in oil & gas pipelines and high-standard structural projects
What Is HSAW Pipe?
HSAW pipes (Helical Submerged Arc Welded pipes) are produced from steel coil that is continuously formed into a spiral shape before welding. As the edges of the coil meet, submerged arc welding is applied along the helical seam, using welding filler material to ensure joint integrity.
Unlike LSAW pipe, HSAW pipe features both inner and outer welds along the spiral seam. This dual-weld structure significantly enhances rigidity and structural stability. As a result, hsaw pipes can be manufactured in larger diameters while maintaining strong tensile and yield strength.
These characteristics make HSAW pipe an efficient and cost-effective choice for large-scale pipeline systems, provided that weld orientation and loading direction are properly considered during design and installation.
Key Features of HSAW Pipe
- Helical weld seam with inner and outer weld reinforcement
- Flexible production for large diameters and long pipe lengths
- High tensile and yield strength
- Efficient manufacturing with cost advantages for large projects
- Widely used in water transmission, piling, and long-distance pipelines
What Is the Difference Between LSAW and HSAW?
Understanding what is the difference between LSAW and HSAW mainly involves four aspects:
Manufacturing Method
LSAW pipe is produced from steel plate with a straight longitudinal weld.
HSAW pipe is produced from steel coil with a continuous helical weld.
Mechanical Performance
