The alphabet soup of pipe standards — ASTM, ASME, API, DIN, EN, JIS, GB — can be bewildering for buyers who simply need the right pipe for their project. Each standard body serves a different industry segment, and the specifications they publish are not interchangeable. This guide maps the major standards to their applications so you can identify which specification belongs on your purchase order.
ASTM: The Material Foundation
ASTM (American Society for Testing and Materials) specifications define the material — the chemistry, mechanical properties, testing requirements, and dimensional tolerances of the pipe itself. When you order ASTM A106 Grade B pipe, you are specifying a carbon steel seamless pipe with defined carbon, manganese, and silicon ranges, minimum yield and tensile strengths, and mandatory hydrostatic testing. ASTM is the material specification; it tells the mill how to make and test the pipe.
Key ASTM pipe specifications include: A106 (high-temperature carbon steel), A53 (general service), A333 (low-temperature), A335 (alloy steel pipe), A213 (alloy and stainless tube), A179 (heat exchanger tube), A519 (mechanical tube), and A500 (structural hollow sections). Each covers a specific material-application combination.
ASME: The Design and Fabrication Code
ASME (American Society of Mechanical Engineers) codes govern how pipe is designed into a system, fabricated, inspected, and pressure-tested. ASME Section II adopts ASTM material specifications with the “SA” prefix (SA 106 is the ASME adoption of ASTM A106), often adding supplementary requirements. ASME B31.1 (Power Piping), B31.3 (Process Piping), B31.4 (Pipeline Transportation of Liquids), and B31.8 (Gas Transmission and Distribution) provide the piping design codes that reference these material specifications.
The critical distinction: ASTM tells you what the pipe is made of; ASME tells you how to use it safely in a pressure system. A piping engineer works with both simultaneously — selecting the ASTM material grade, then applying the ASME code to determine wall thickness, pressure rating, joint design, and testing requirements.
API: Upstream Oil and Gas
API (American Petroleum Institute) specifications cover pipe products for the upstream and midstream oil and gas industry. API 5L governs line pipe for transportation of petroleum and natural gas. API 5CT covers casing and tubing for wellbore service. API 5DP covers drill pipe. These specifications include grade designations, testing protocols, and quality systems specific to the demands of drilling, completion, and pipeline operations.
API specifications are not alternatives to ASTM — they are parallel standards designed for a specific industry. A refinery might use ASTM A106 pipe for its process piping and API 5L pipe for its pipeline connections within the same facility, each selected under its relevant design code.
European and International Standards
EN (European Norm) standards have progressively replaced national standards across Europe. EN 10216 covers seamless steel tubes for pressure purposes (Part 1: non-alloy, Part 2: non-alloy and alloy with elevated temperature properties, Part 5: stainless steel). EN 10210 and EN 10219 cover structural hollow sections. These standards are broadly equivalent to their ASTM counterparts but use different grade designations, test methods, and acceptance criteria.
DIN (German Institute for Standardisation) standards such as DIN 1629 and DIN 2391 remain in common use for specific applications, particularly hydraulic tubes and general-purpose seamless pipe in projects with German engineering heritage. JIS (Japanese Industrial Standards) G3452, G3454, and G3456 serve similar roles in Japanese-engineered projects.
Putting It Together on a Purchase Order
A complete pipe purchase order references the material specification (ASTM/EN/API), the grade within that specification, the dimensional standard (ASME B36.10 for pipe, B36.19 for stainless, or metric per EN), and the governing design code. Missing any one of these can result in material that technically meets a specification but is unsuitable for the intended service. When in doubt, provide the piping line class or spec sheet from your project — it contains all the information a manufacturer needs to quote correctly.
Need guidance on the right specification for your project? Contact our technical team — we work across ASTM, API, EN, DIN, and JIS standards daily.