Seamless Ferritic Alloy-Steel Pipe for High Temperature Service. This specification covers both nominal and minimum wall thickness.

U.S. Metals is a leading steel supplier of A335/SA335 grade P11 High Pressure Alloy Steel Seamless Pipe. These pipes can be customized to suit the size and shape needs of each of our clients.

Our steel piping inventory is unsurpassed. From the first phone call, you will notice a big difference in our inventory availability and customer service. We have seasoned professionals available to discuss all of you piping needs.

U. S. Metals stocks ASTM /ASME A/SA P11 Pipe, Heater Tubes, Fittings, Flanges and Valves from ½” NPS through 30” NPS with wall thickness ranging from STD through 4” Thick. We are considered to have the largest inventory of P11 High Energy Pipe, Fittings, Flanges & Valves. USM stock also consists of Minimum Wall Thickness pipe as well as material certified to ASTM/ASME A/SA 213 which is required by some power plant equipment designs. Go to the U. S. Metals comparison chart titled The Difference Between ASTM A213 and ASTM A335 for more information on the difference between P11 and T11.

About ASTM A335 P11 Pipe

Trade Name: 1 ¼ Chrome
Grade: P11
UNS #: K11597
Pipe: A335/SA335
Forged/Bored Pipe: A369/SA369

Chromium and molybdenum are important elements of P11. Chromium, or chrome, improves high-temperature strength, increases oxidation resistance and raises the tensile, yield and hardness at room temperatures. Molybdenum increases the strength, elastic limit, resistance to wear, impact qualities and hardenability. It increases the resistance to softening, restrains grain growth and makes chromium steel less susceptible to embrittlement. Moly is also the most effective additive for increasing high temperature creep strength, or creep resistance. It also enhances the corrosion resistance of steel and inhibits pitting.

P11 Pipe Chemical Requirements

  • Carbon - 0.05% - 0.15%
  • Manganese - 0.30% - 0.60%
  • Phosphorus, max - 0.025%
  • Sulfur, max - 0.025%
  • Silicon – 0.50% - 1.00%
  • Chromium - 1.00% - 1.50%
  • Molybdenum - 0.44% - 0.65%

Enhanced properties of A335/SA335 P11

  • Toughness
  • Strength
  • Hardness
  • Wear resistance
  • Hardenability
  • Hot hardness
  • Corrosion resistance

Heat treating can be required to achieve some of these properties.


P11 Pipe Specifications

  • Tensile strength, min, PSI, (MPa) – 60,000 (415)
  • Yield Strength, min, (MPa) – 30,000 (205)

P11 Pipe Applications

Due to the ferrimagnetic characteristics of iron, a few steel alloys in A335 P11 pipes can be used in applications where their reactions to magnetism are important. This includes transformers and electric motors. P11 is also a popular grade for many different applications such as:

  • Spacecraft
  • Turbine blades of jet engines
  • Nuclear reactorst

Call U.S. Metals today to learn more about our Chrome Moly Alloy Seamless P11 Pipe inventory today.