ASME SA553 Type 1 9% Nickel Steel Sheet with Low-Temperature Toughness for Cryogenic Pressure Vessels

ASTM A553 Type 1 is a high-nickel alloy steel plate specification issued by ASTM International (formerly the American Society for Testing and Materials). The material is colloquially called "9% nickel steel" because its nickel content ranges from 8.50% to 9.50% by weight.

The steel combines high tensile strength (690-825 MPa) with exceptional low-temperature toughness, making it one of the most widely specified materials for cryogenic pressure vessels operating at temperatures down to −196 °C (−320 °F).

• Decades of proven service: ASTM A553 Type I has been used reliably for LNG and cryogenic containment since the 1960s
• Martensitic microstructure with high toughness: Unlike conventional martensitic steels, A553 remains ductile rather than brittle at cryogenic temperatures
• Good weldability: Designed for welded pressure vessel fabrication, compatible with nickel-based welding consumables
• Availability across supply chains: As an ASTM standard, mills and distributors worldwide recognize and stock A553 Type 1 plates

Your selection path can ultimately be summarized as: Choose ASTM A553 Type 1 when your project does not need ASME Code stamping but still demands full cryogenic performance - the material is identical to SA553.

ASME SA553 Type 1 is the same 9% nickel alloy steel - identical in chemical composition, mechanical properties, and heat treatment requirements to ASTM A553 Type 1. The key difference is the standard-issuing body: ASME (the American Society of Mechanical Engineers) adopts ASTM material specifications into its Boiler & Pressure Vessel Code (BPVC) by adding an "S" prefix.

• The ASME SA-553 specification is published in ASME BPVC Section II, Part A, which governs ferrous material specifications for pressure vessel construction
• When a pressure vessel is designed, fabricated, inspected, and stamped in accordance with ASME BPVC Section VIII, the materials used must (in most jurisdictions) ry ASME designations
• That's the single biggest reason a buyer might need "SA553" rather than "A553" plates: regulatory compliance, not any metallurgical difference

Choose ASTM A553 Type 1 If:

• Your project only requires ASTM material compliance
• Pressure vessel code certification is not mandatory
• General cryogenic engineering applications are involved

Choose ASME SA553 Type 1 If:

• Your project falls under ASME BPVC regulations
• Pressure vessel certification is required
• International EPC standards must be followed
• LNG terminal projects require code compliance