EN10217 Straight Seam Welded Steel Tube

Manufacturing Process

Electric Resistance Welded (ERW): Cold-forming steel strip into a cylinder, then resistance heating to forge a straight longitudinal weld; typical for medium-small diameters (10.2–610 mm).

Submerged Arc Welded (SAW): Using flux-shielded arc welding for heavy plates/strips; suited for large-diameter, thick-wall tubes (often ≥ 323.9 mm OD) requiring high weld integrity.

All tubes undergo strict dimensional control, weld heat treatment (if required), and mandatory pressure/non-destructive testing.

Material & Dimensional Requirements

Chemical & Mechanical: Grades marked Pxxx (P=Pressure, xxx=minimum yield strength in MPa); GH=high temperature, NL=normalized low temperature. Example: P235GH (235 MPa yield, elevated temp service); P355NL1 (355 MPa yield, normalized, low-temp impact grade 1).

Dimensions: OD typically 219mm–820 mm, wall thickness 5-22mm; OD tolerance ±0.4 mm (≤48.3 mm) to ±1% (＞114.3 mm); wall thickness tolerance ±10% or tighter per part; standard lengths 6–12 m, with custom  available.