ASTM A53 Grade B seamless pipe is a carbon steel pipe used for low-pressure plumbing, mechanical, pressure and structural applications. Unlike ASTM A106, which focuses on high-temperature service, A53 covers both seamless and welded pipe in three grades: A, B and C, with Grade B being the most common choice for general service. Huaxia-Steel supplies A53 Gr B seamless pipe with plain, beveled or threaded ends and full certification.

Product Overview
Our A53 Grade B seamless pipe is produced by hot piercing and rolling, then cooled, straightened, cut and inspected. The grade offers good weldability, moderate strength and is suitable for water, steam, gas and air lines as well as structural and mechanical uses.
Specifications and Size Range
| Item | Specification |
|---|---|
| Standard | ASTM A53 / A53M |
| Grade | Grade B |
| Type | Seamless (S) and Electric-Resistance-Welded (E) |
| NPS | 1/8 inch – 26 inch |
| Outer diameter | 10.3 mm – 660 mm |
| Wall thickness | Sch 10 – Sch XXS / custom |
| Length | 5.8 m / 6 m / 11.8 m / 12 m or custom |
| Ends | Plain, beveled, threaded with couplings |
Chemical Composition
| Element | Limit |
|---|---|
| Carbon max | 0.30 % |
| Manganese | 1.20 % max |
| Phosphorus max | 0.05 % |
| Sulfur max | 0.045 % |
| Silicon | 0.10 % min when silicon steel is required |
| Copper + Nickel + Chromium + Molybdenum | 1.00 % max combined |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile strength min | 415 MPa |
| Yield strength min | 240 MPa |
| Elongation | Depends on wall thickness; see ASTM A53 |
| Hardness | Not specified; tested when required |
Testing and Certification
ASTM A53 requires hydrostatic testing or non-destructive electric testing. We supply mill test certificates showing heat analysis, tensile test, hydrostatic or NDE result and dimensional inspection. Third-party inspection by SGS or BV is available.
- Hydrostatic test to specified pressure or 100 % NDE.
- Flattening test for seamless pipe.
- Bend test for welded pipe.
- Chemical analysis and tensile test per heat.
- Ultrasonic or eddy-current testing on request.

Applications
- Low-pressure steam, water, gas and air lines.
- Structural and mechanical tubing.
- Fence posts, handrails and general construction.
- Conveyor rollers and machinery frames.
- Fire protection systems (when compatible with local code).
- General plumbing and process piping where high temperature is not the primary factor.
Equivalent Grades
ASTM A53 Gr B is roughly equivalent to several international grades for low-pressure piping and structural applications.
| Standard | Close Equivalent | DIN | JIS |
|---|---|---|---|
| ASTM A53 Gr B | API 5L Gr B | DIN 2391 St 45 | JIS G3454 STPG 370 |
| ASTM A106 Gr B | API 5L Gr B | DIN 17175 St 45.8 | JIS G3456 STPT 370 |
Packing and Shipping
Pipe is bundled with steel straps, ends capped to prevent ingress and damage, and loaded in containers or on flat racks. Black paint, oil coating or varnish can be applied for rust protection during ocean shipment.

Need a reliable carbon steel supplier for your next project? Huaxia-Steel supplies mill-certified carbon steel bars, plates, pipes, flanges and fittings with full inspection, export packing and fast delivery. Request a quote today and our team will reply within 24 hours.





