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What are the differences between A106 and A53?
Date:2020-11-19      View(s):73      Tag:What are the differences between A106 and A53?

ASTM A53 pipes and ASTM A106 pipes are very similar,they are the most commonly used carbon steel pipes for industry applications. Although the differences between ASTM A53 pipes and ASTM A106 pipes are few,they differ greatly in the time and place specified

ASTM A53 is Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless.

ASTM A106 is Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service.

API 5L is Specification for Line Pipe.


A 53 is a general steel pipe spec which covers galvanized pipe and black pipe. It is available in Type S (seamless), Type E (ERW, electric resistance welded longitudinal seam), and Type F (furnace welded).

A106 Gr. B is intended for high temperature service (up to 750 Deg F). It just applies to seamless steel pipe with killed steel. Pipe of NPS 1 1/2” and under may be either hot finished or cold drawn. Unless specified, pipe on and over NPS 2″ shall be furnished hot finished, while A53 and API 5L are not.

API 5L Gr. B (PSL-1) is mainly developed for Line pipes used in conveying gas, oil, and water in oil and gas industry. Either seamless steel pipe or welded pipe is OK.

Chemical compositions of ASTM A53 Pipes VS ASTM A106 Pipes:
The chemical composition difference between ASTM A106 and ASTM A53 can be obtained from the following table:

1. ASTM A106 contains silicon with a minimum content of 0.10%.ASTM A53 don’t contain silicon.Silicon as an alloying element improves heat resistance in ASTM A106 pipe,which is rated for high-temperature service.Without it,regular exposure to high temperatures can weaken pipe over time,increasing its risk of failure.

2. ASTM A53 and ASTM A106 have different manganese content.

3. ASTM A106 and ASTM A53 standards contain varying amounts of sulfur and phosphorus,and the maximum content of ASTM A106 standard is 0.035%.The content of sulfur and phosphorus in ASTM A53 was 0.05 and 0.045% respectively.These elements are normally considered impurities in steel,so their incorporation in piping is minimal. However, the trace amounts of these elements add machinability to steel pipe.

Chemical compositions

Standard Grade Chemical Composition %
C Mn P S Si Cr Cu Ni Mo V
ASTM A106 B ≤0.30 0.29-1.06 ≤0.035 ≤0.035 >0.10 ≤0.40 ≤0.40 ≤0.40 ≤0.15 ≤0.08
ASTM A53 B ≤0.30 ≤1.20 ≤0.05 ≤0.045 ≤0.40 ≤0.40 ≤0.40 ≤0.15 ≤0.08
API 5L B(PSL-1) ≤0.28 ≤1.20 ≤0.030 ≤0.030
DIN 1629,
DIN 2448
St 37.0 ≤0.17 ≤0.040 ≤0.040
St 44.0 ≤0.21 ≤0.040 ≤0.040
EN10210 S235JRH ≤0.17 ≤1.40 ≤0.040 ≤0.040
10# 0.07-0.13 0.35-0.65 ≤0.035 ≤0.035 0.07-0.37 ≤0.15 ≤0.25 ≤0.30
20# 0.17-0.23 0.35-0.65 ≤0.035 ≤0.035 0.17-0.37 ≤0.25 ≤0.25 ≤0.30

Mechanical properties

Standard Grade Tensile Strength
Yield Strength
Impact Test
ASTM A106 B >415 ≥240 ≥16.5
ASTM A53 B >415 ≥240
API 5L B(PSL-1) >414 ≥241 As clause a
DIN 1629 St 37.0 350-480 ≥235 ≥23
DIN 2448 St 44.0 420-550 ≥275 ≥19
EN10210 S235JRH 360-510 ≥235 ≥26 27 (+20°C)
GB/T 8163 10# 335-475 ≥205 ≥24
GB/T 8162 20# 410-550 ≥245 ≥20

A53 is usually for defining welded pipe, while A106 for seamless. If you ask for A53, suppliers will also quote A106 or API 5L as an alternate.

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