ASTM/ ASME A106/SA106 Seamless Carbon Steel Pipe

Elevated silicon content improves heat resistance in industrial applications.

U. S. Steel Tubular Products ASTM/ASME A106/SA106 seamless carbon steel pipe is used in industrial applications involving high heat, including process piping, boiling plants, compression stations and refineries. The additional silicon boosts this product’s performance in high-temperature environments, such as steam lines and processing applications.

U. S. Steel Tubular Products offers the widest variety of sizes available in the industry. All of our products are domestically sourced, developed, and produced, which means our customers have immediate access to exactly the products they need for their particular application. And, because our products are domestic, you are assured of the highest quality and manufacturing standards and a local, concerned, customer service presence.

A106 Comparative Specifications

ASTM Specification A106 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. Surface finish standards are outlined in the specification.

Purchaser may specify NDE in lieu of hydrostatic test or neither. Unless otherwise specified, pipe is furnished with plain ends.

Mechanical Properties – Tensile Requirements

  Grade A Grade B Grade C
Tensile Strength, min, psi 48,000 60,000 70,000
Yield Strength, min, psi 30,000 35,000 40,000

Chemical Requirements

Element Grade A Grade B Grade C
Carbon max. % 0.25 0.30 0.35
Manganese % 0.27 – 0.93  0.29 – 1.06  0.29 – 1.06 
Phosphorus max %   0.035 0.035 0.035
Sulfur max % 0.035 0.035 0.035
Silicon, min % 0.10 0.10 0.10
  • Testing Requirements for seamless A106 carbon steel pipe
    • 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 2,500 psi for NPS 3 and under, and 2,800 psi for the larger sizes. Pressure is maintained for no less than 5 seconds.
    • Mechanical Tests:
      • Tensile Test: Either transverse or longitudinal are acceptable for NPS 8 and larger
      • Tensile tests smaller than NPS 8: Longitudinal testing only
      • Flattening Test: NPS 2 and larger
      • Bending Test (cold): NPS 2 and under
        Degree of Bend   Diameter of Mandrel
      For normal A106 uses    90  12x nominal diameter of pipe
      For close coiling 180  8x nominal diameter of pipe
    • Number of Tests: One tensile test per 200 lengths.
  NPS  On one length from each lot of:
Tensile 5 and smaller   400 or less
  6 and larger      200 or less
Bending 2 and smaller 400 or less
Flattening 2 through 5 400 or less
  6 and larger 200 or less
  • Permissible Variations in Dimension
    • Wall thickness: The minimum wall thickness at any point shall not be more than 12.5% under the nominal wall thickness specified.
    • Weights per foot: The weight of any individual length shall not vary more than 10% over and 3.5% under that specified. NOTE – NPS 4 and smaller are weighed in lots. Larger sizes are weighted by individual length.
    • Outside diameter: Shall not vary from standard specified below at any point.
NPS Over Under
1 ½ and smaller  +1/64” -1/64”
2-4 +1/32” -1/32”
5-8 +1/16” -1/32”
10-18 +3/32” -1/32”
Over 18 +1/8” -1/32”
  • Lengths of A106 seamless carbon steel pipe
    Lengths of U. S. Steel Tubular Products A106 seamless carbon steel pipe must be specified on order. No “jointers” are permitted unless otherwise specified. If no definite lengths are required, the following practice applies:
    • Single random – 16’ – 22’ (5% may be 12’ – 16’)
    • Double random – Minimum length is 22’. Minimum average is 35’ (5% may be between 16’ – 22’)
  • Marking Requirements
    Rolled, die stamped, or paint stenciled (manufacturer’s option).
    • Manufacturer’s name, brand, or trademark
    • A106 A, A106 B, or A106 C
    • Hydrostatic test pressure and/or NDE, or NH if neither is specified
    • Size, length, weight per foot (NPS 4 and larger)
    • ANSI schedule number or weight class or wall thickness
    • Additional “S” if tested supplementary requirements

U. S. Steel Tubular Products A106 seamless carbon steel pipe

U. S. Steel Tubular Products are available through authorized distributors across North America. See our complete U. S. Steel Tubular Products Standard & Line Pipe Distributor list here.

U. S. Steel Certifications

U. S. Steel Tubular Products seamless pipe facilities meet the internationally recognized quality system requirements of ISO9001 and API Q1 and our seamless facilities hold a PED certifications See the complete list of U. S. Steel Tubular Products certifications.