1. DIN 17100 - The Base Material Standard (Historical)
DIN 17100 was the classic German standard for "Steels for General Structural Purposes; Quality Standards." It has been largely superseded by the European standard EN 10025-2 (and following parts).
Key Concept: It specifies the steel plate, not the pipe.
Common Grades: St 37, St 44, St 52 (The number indicates the minimum yield strength in kgf/mm², e.g., St 37 ≈ 235 MPa yield).
These grades are known for good weldability and toughness, making them ideal raw material for welded pipes.
Important: While still used in specifications, for new designs, EN 10025-2 grades like S235JR, S355JR, or S355J2 are the direct modern equivalents.
2. Longitudinally Submerged Arc Welded (L-SAW) Pipe - The Product
This describes the pipe manufacturing process:
Steel plates (conforming to DIN 17100) are formed and the longitudinal seam is welded inside and out using the Submerged Arc Welding process.
This results in a high-quality, high-strength weld suitable for demanding applications.
3. The Correct Pipe Standards (Which Reference or Use DIN 17100 Steel)
The finished L-SAW pipe is certified under specific product standards. The most relevant German/European standards are:
| Standard | Title & Scope | Connection to DIN 17100 / Modern Equivalents |
|---|---|---|
| DIN 2458 | Longitudinally welded steel tubes for mechanical and general engineering purposes. | This is the primary standard for general structural L-SAW pipes in the German system. It directly references steel grades like St 37.0, St 44.0, St 52.0 from DIN 17100. |
| DIN 1626 | Welded circular steel tubes for general purposes; Technical delivery conditions. | Another key standard for welded tubes, covering a wider range. It also references structural steels. |
| EN 10219-1/-2 | Cold formed welded structural hollow sections of non-alloy and fine grain steels. | While often for smaller sections, it covers welded tubes from steel grades like S235, S355 (the EN successors to St37/St52). |
| API 5L / ISO 3183 | Line Pipe | For high-pressure fluid transmission (oil, gas). Uses entirely different, pipe-specific steel grades (e.g., B, X42, X70). Not typically associated with DIN 17100. |
Typical Specification for a "DIN 17100 L-SAW Pipe"
A complete technical and ordering specification would combine the product standard and the material standard:
Longitudinally Submerged Arc Welded Pipe to DIN 2458, Grade St 52.0
Material: DIN 17100 St 52-3 (or modern equivalent: EN 10025-2 S355J2)
Dimensions: OD 508 mm, WT 12.5 mm, Length 12,000 mm
Delivery Condition: As welded (+N) or normalized (+N)
Testing: As per DIN 2458, including tensile test, bend test on weld seam, flattening test, and often ultrasonic testing (UT) of the longitudinal weld.
Key Points & Modern Context
Material vs. Product: DIN 17100 defines the steel plate's chemical and mechanical properties. DIN 2458 defines the tolerances, testing, and acceptance criteria for the finished pipe made from that plate.
Modern Equivalents: In contemporary European projects, you will more likely see:
Pipe: EN 10219 or DIN 2458
Steel Grade: EN 10025-2 (e.g., S355J2H for hollow sections) instead of DIN 17100 St 52-3.
Application: Such pipes are used for structural columns, piling, heavy equipment frames, conveyors, and industrial plant construction-where high static and dynamic loads are present.
Summary
A "DIN 17100 Longitudinally Submerged Arc Welded Pipe" is accurately described as:
A longitudinally welded steel pipe, manufactured according to a product standard like DIN 2458, using steel plates that conform to the material specifications of DIN 17100 (or its modern EN 10025 equivalents).
The terminology persists in industry for clarity and historical preference, but the complete technical definition requires both the pipe standard and the material standard.
