Differences Between The A106 Grade B Seamless Pipe And A53 Grade B SMLS Pipe

- Jun 07, 2018-

Today i am going to explain the differences between these three most commonly requested materials - A106B, A106C and A53B seamless pipes.

A106 is only manufactured based on a seamless product and is available in three grades; A & B & C. 

A53 comes in two grades and three types. A53 can be produced as a seamless product (A53 Grade A Type S (Seamless) and A53 Grade B Type S (Seamless) or as a welded product (A53 Grade B Type E (Welded), A53 Grade A Type E (Welded) or A53 Grade A Type F (Welded)).


Comparison Chart:

Chemical Composition:

StandardGrade ProcessChemical Composition %
C maxMn*P maxS maxSi minCr˟ maxCu˟ maxNi˟ maxMo˟ maxV˟ max
ASTM A106-15BSMLS0.30*0.29-1.060.0350.0350.100.400.400.400.150.08
ASTM A106-15CSMLS0.35*0.29-1.060.0350.0350.100.400.400.400.150.08
ASTM A53-12BSMLS0.30*
*For each reduction of 0.01% below the specified carbon maximum, an increase of 0.06% manganese above the specified maximum will be permitted up to a maximum of 1.65%.
xThe sum of these five elements shall not exceed 1% (1.00% for A53)
---No requirement for this element

Mechanical Properties:


ProcessTensile Strength (MPa) MinYield Strength (MPa) MinElongation in 2” (%) MinimumLong. Strip TestElongation in 2” (%) MinimumTrans. Strip Test
ASTM A106-15BSMLS60,000 [415]35,000 [240]3016.5
ASTM A106-15CSMLS70,000 [485]40,000 [275]3016.5
ASTM A53-12BSMLS60,000 [415]35,000 [240]30See Spec


StandardPermissible Variations in Outside Diameter
ASTM A53-121-1/2 and less1/64” (0.015”)1/64” (0.015”)
ASTM A53-122 and over1% of OD1% of OD
ASTM A106-151/8 to 1-1/21/64” (0.015”)1/64” (0.015”)
ASTM A106-15 Over 1-1/2 to 41/32” (0.031”)1/32” (0.031”)
ASTM A106-15Over 4 to 81/16” (0.062”)1/32” (0.031”)
ASTM A106-15Over 8 to 183/32” (0.093”)1/32” (0.031”)
ASTM A106-15Over 18 to 261/8” (0.125”)1/32” (0.031”)
ASTM A106-15Over 26 to 345/32” (0.156”)1/32” (0.031”)
ASTM A106-15Over 34 to 483/16” (0.187”)1/32” (0.031”)