Seamless Steel Pipe Manufacturing Standards

The global mainstream seamless steel pipe (SMLS) manufacturing standard system is mainly divided into two categories: general standards and special standards. Specifically:

General Material and Delivery Technical Condition Standards:

These standards are fundamental, specifying chemical composition, mechanical properties, dimensional tolerances, test methods, and delivery conditions.

1. American Standards (ASTM/ASME)

ASTM A106: Seamless carbon steel tubes for high-temperature applications
ASTM A53: Seamless and welded steel tubes (general purpose)
ASTM A335: Ferritic alloy steel seamless tubes for high-temperature applications
ASTM A213: Alloy steel seamless tubes for boilers, superheaters, and heat exchangers

Characteristics: The most widely used industrial standard globally. Grades such as Gr. B, P11, P22, T11, and T22 are universal engineering standards worldwide.

2. European Standards (EN)

EN 10216: Seamless steel tubes for pressure applications
EN 10216-1: Non-alloy and alloy steels
EN 10216-2: Stainless steel
EN 10210: Hot-formed structural hollow sections (seamless/welded)

Characteristics: Mandatory standards for market access in Europe. The grade system is named according to the minimum yield strength, such as P235GH, 25CrMo4, S355J2H.

3. Chinese National Standards (GB)

GB/T 8162: Seamless steel tubes for structural applications
GB/T 8163: Seamless steel tubes for fluid transport
GB 5310: Seamless steel tubes for high-pressure boilers
GB 9948: Seamless steel tubes for petroleum cracking

Characteristics: The fundamental basis for design, manufacture, and acceptance in China. Common grades include 20#, 45#, Q345, 15CrMoG, etc.

4. German Standards (DIN)

DIN 2448/DIN 1629 (partially superseded by EN)

Characteristics: Traditional industrial standards, still used in many older drawings and technical documents.

5. Japanese Standards (JIS)

JIS G3441: Carbon steel pipes for mechanical structures
JIS G3454: Carbon steel pipes for pressure piping
JIS G3458: Alloy steel pipes for high-temperature piping

Characteristics: Widely influential in East and Southeast Asia. Grades such as STKM, STS, STPA.

6. International Standards (ISO)

ISO 2937: Seamless steel pipes for mechanical engineering
ISO 9329: Seamless steel pipes for pressure applications

Characteristics: Aimed at harmonizing global standards, but less influential in the industrial sector than ASTM and EN.

Industry-Specific Product Standards:

These standards, based on general standards, add more stringent additional requirements, applicable to specific high-risk or critical areas.

1) Oil and Gas

API 5L: Line Pipe Specification
API 5CT: Casing and Tubing Specification

Characteristics: API 5L is the highest authoritative standard in the energy industry, covering various steel grades from GR.A to X100, emphasizing weldability, toughness, and strict dimensional and weight tolerances. API 5CT has special requirements for threading, crush resistance, and corrosion resistance.

2) Boilers and Pressure Vessels

ASME SA-106: Seamless Carbon Steel Tube Specification for High Temperature Pressure Use
ASME SA-213: Seamless Ferritic and Austenitic Alloy Steel Tube Specification for Boilers, Superheaters, and Heat Exchangers

Common Materials:

ASME SA-106: Main grades are Gr. A, Gr. B, Gr. C.

ASME SA-213: 

Ferritic alloy steels: such as T11, T22, T91, T92. These steels have good high-temperature strength and creep resistance.

Austenitic stainless steel: such as TP304H, TP316H, TP347H. This type of steel has excellent resistance to high-temperature oxidation and corrosion.

Characteristics: While ASME and ASTM standard numbers are the same, when materials are used in boilers and pressure vessels governed by ASME specifications, they must conform to the "SA" version of ASME Section II, Part A, which may be more stringent than commercial ASTM standards. SA-213 is much more demanding than general seamless pipe standards (such as ASTM A106).

3) Automotive and Machinery Industry

DIN 2391: Precision Seamless Steel Tubes and internal standards for various automotive manufacturers
Characteristics: Extremely high requirements for dimensional accuracy (e.g., h8, h9 grades), surface finish, and heat treatment conditions.

4) Marine and Ocean Engineering

National classification society standards such as: LR, DNV, ABS, CCS.

Characteristics: Requires materials to be certified by the classification society, including additional impact testing, more stringent non-destructive testing, and specific heat treatment requirements.

Key Requirements Covered by the Standard:

a. Chemical Composition: Limits on the content of elements such as carbon (C), manganese (Mn), chromium (Cr), and molybdenum (Mo).
b. Mechanical Properties: Tensile strength, yield strength, elongation, and hardness.
c. Dimensions and Tolerances: Diameter, wall thickness, and length.
d. Manufacturing Process: Specifies seamless production (no welding).
e. Testing and Inspection: Hydrostatic testing, non-destructive testing (NDT) (e.g., ultrasonic or magnetic particle testing), and visual inspection for defects (cracks, delamination).
f. Surface Treatment: Threading, coating, and end caps.
g. Documentation: Factory Test Certificate (MTC), e.g., EN 10204 (3.1, 3.2).

Selection Notes: 

ASTM/ASME, API, and EN are the three major global standard systems. For international trade and critical projects, it is essential to provide complete and accurate standard numbers, grades, specifications, and additional requirements when procuring. This is the only reliable way to ensure you receive the products you need.

Read more: Seamless Steel Pipe Sizes and Weights