A106 Pipe Specifications

NPS 1/4″- 30″
Schedules 10 through 160, STD, XH and XXH


ASTM A106 Seamless Pressure Pipe (also known as ASME SA106 pipe) covers seamless carbon steel nominal wall pipe for high-temperature service. Suitable for bending, flanging and similar forming operations.

NPS 1-1/2″ and under may be either hot finished or cold drawn. NPS 2″ and larger shall be hot finished unless otherwise specified.


Killed steel, with primary melting process being open-hearth, basic-oxygen, or electric-furnace, possibly combined with separate degassing or refining.

Steel cast in ingots or strand cast is permissible.

Hot-finished pipe need not be heat treated.

Cold-drawn pipe shall be heat treated after the final cold draw pass.

Chemical Requirements

Grade AGrade BGrade C
Carbon max. %0.250.300.35
*Manganese %0.27 to 0.93*0.29 to 1.060.29 to 1.06
Phosphorous, max. %0.0350.0350.035
Sulfur, max. %0.0350.0350.035
Silicon, min.%
Chrome, max. %0.400.400.40
Copper, max. %0.400.400.40
Molybdenum, max. %
Nickel, max. %0.400.400.40
Vanadium, min.%

Total of Cr, Cu, Mo, Ni, and V shall not exceed 1%

Permissible Variations in Wall Thickness

The minimum wall thickness at any point shall not be more than 12.5% under the nominal wall thickness specified.

Permissible Variations in Weights per Foot

Weight of any length shall not vary more than 10% over and 3.5% under that specified. NOTE — NPS 4 and smaller — weighed in lots. Larger sizes shall be weighed separately by length.

Permissible Variations in Outside Diameter

Outside Diameter at any point shall not vary from standard specified more than:

NPS [DN Designator]OverUnder
1/8 to 1-1/2 [6 to 40], incl1/64 (0.015)0.41/64 (0.015)0.4
Over 1-1/2 to 4 [40 to 100], incl1/32 (0.031)0.81/32 (0.031)0.8
Over 4 to 8 [100 to 200], incl1/16 (0.062)1.61/32 (0.031)0.8
Over 8 to 18 [200 to 450], incl3/32 (0.093)2.41/32 (0.031)0.8
Over 18 to 26 [450 to 650], incl1/8 (0.125)3.21/32 (0.031)0.8
Over 26 to 34 [650 to 859], incl5/32 (0.156)4.01/32 (0.031)0.8
Over 34 to 48 [850 to 1200], incl3/16 (0.187)4.81/32 (0.031)0.8

Tensile Requirements

 Grade AGrade BGrade C
Tensile Strength, min., psi48,00060,00070,000
Yield Strength, min., psi30,00035,00040,000

Number of Tests Required

NPS On One Length from Each Lot of
Tensile5 and smaller400 or less
6 and larger200 or less
Bending2 and smaller400 or less
Flattening2 through 5400 or less
6 and over200 or less

Hydrostatic Testing

Inspection test pressures produce a stress in the pipe wall equal to 60% of specified minimum yield strength (SMYS) at room temperature. Maximum Pressures are not to exceed 2500 psi for NPS3 and must stay under 2800 psi for the larger sizes. Pressure is maintained for not less than 5 seconds.

Mechanical Tests Specified

Tensile Test — NPS 8 and larger — either transverse or longitudinal acceptable Smaller than NPS 8 — weighed in lots. Larger sizes — by length. Flattening Test — NPS 2-1/2 and larger. Bending Test (Cold) — NPS 2 and under.

Degree of BendDiameter of Mandrel
For Normal A106 Uses9012 x nom dia. of pipe
For Close Coiling1808 x nom dia. of pipe


Lengths required shall be specified on order. No “jointers” permitted unless otherwise specified. If no definite lengths required, following practice applies: Single Random — 17′ ~ 24′ lengths Double Random — 36′ ~ 44′ lengths

Required Markings on Each Length

(On Tags attached to each Bundle in case of Bundled Pipe) Rolled, Stamped, or Stenciled (Mfrs. Option) Manufacturer’s name or brand. Length of pipe. A106 A, A 106 B, A 106 C. ANSI schedule number. Hydrostatic test pressures and/or NDE; Weight per foot (NPS 4 and larger) or NH if neither is specified. Additional “S” if tested supplementary requirements.

Referenced Documents

  • ASTM A 530/A 530M Specification for General Requirements for Specialized Carbon and Alloy Steel Pipe
  • ASTM E 213 Practice for Ultrasonic Examination of Metal Pipe and Tubing
  • ASTM E 309 Practice for Eddy-Current Examination of Steel Tubular Products Using Magnetic Saturation
  • ASTM E 381 Method of Macroetch testing Steel Bars, Billets, Blooms, and Forgings
  • ASTM E 570 Practice for Flux Leakage Examination of Ferromagnetic Steel Tubular Products
  • ASME B26.10M Welded and Seamless Wrought Steel Pipe

General Information

Orders for material under this specification should include the following, as required, to describe the desired material adequately:

QuantityFeet, centimeters, or number of lengths
Name of materialSeamless or Welded Pipe
GradeGrade A, Grade B, or Grade C
ManufactureHot-finished or cold-drawn
SizeNPS or Outside Diameter and Schedule Number of Average Wall Thickness
Special outside diameter tolerance pipe
Inside diameter tolerance pipe, over 10 in ID
LengthSpecific or random
Supplementary requirements
Test Report Required
Specification designation
Hydrostatic test
Special requirements


*ASTM A 106 grade B Seamless Pressure Pipe

B) Unless otherwise specified by the purchaser, 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 %.

*ASME SA 106 grade B Seamless Pressure Pipe

B) 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 1.35 %.