ASTM A335 P91 Pipes is a high temperature service pipe that is used in petroleum industries the most. These pipes are used to transport hot fluids over long lines of pipes. Oil, gas and water lines are constructed with these pipes.

ASTM A335 P91 Pipes
A335 P91 Material SA335 Grade P91

Hi-tech Metal & Tubes is one of the largest P91 Pipes suppliers and we produce these pipes in different shapes, sizes and grades for use in different application types. The A335 P91 Material consists of chromium, molybdenum and nickel and manganese in smaller quantities. The molybdenum addition in the SA335 Grade P91 makes it stronger and more corrosion resistant. The manganese and nickel components provide the hardenability of the pipes. There are A335 P91 Welded Pipes types as well as the seamless pipes types. The ASTM A335 P91 Pipes could be heat treated to harden it. The P91 Seamless Pipes is used in applications which require precise dimensions. The pipes can range from 3/8 inches to 30 inches in diameter. There are plain end, beveled end and threaded end of P91 Pipes products. We supply all the different types and sizes according to customer needs. Please contact us for further information on the A335 P91 pipes and for custom orders.


ASTM A335 P91 Alloy Steel Seamless Pipe material properties are that it could be a blend of 1 % Molybdenum and 9 % Chromium. Because of the presence of Molybdenum, the crawl resistance of the material is expanded. As a result of Chromium being show within the material, its oxidation resistance is increased and it moreover gets high temperature quality.

ASTM A335 P91 Chemical Composition Standard

Alloy Steel P91 C Cr Mn Mo P S Si
0.08-0.12 8.00 – 9.50 0.30-0.60 0.85 – 1.05 0.020 max 0.010 max 0.20 -0.50

Mechanical Analysis of ASTM A335 P91

Tensile Strength, MPa Yield Strength, MPa Elongation
585 min 415 min 20 min

A335 P91 Welded Pipe Specification list

ASTM A335 P91 Pipe Standard ASTM A335 P91, SA335 P91
SA335 Grade P91 Thickness 3 To 12 Mm
SA335 P91 Material Tolerance Cold drawn pipe: +/-0.1 MM
Cold rolled pipe: +/-0.05 MM
ASTM A335 P91 Pipes Type Seamless / ERW / Welded / Fabricated
A335 P91 Welded Pipes Schedules Schedule 40, 80, 160, XS, XXS
A335 Gr P91 Pipes Size 1/2 Inch NB to 36 Inch NB

Equivalent of ASTM A335 P91 Alloy Steel Pipe

ASTM ASME Equivalent material JIS G 3458 UNS BS DIN ISO ABS NK LRS
A335 P91 SA335 P91 T91, K90901, X10CrMoVNb9-1, 1.4903 K91560