ASTM A203 Grade A is a nickel‑alloy pressure vessel steel designed for welded equipment operating at low temperatures. With its 3.5% Ni composition, A203 Gr.A provides excellent toughness, stable weldability, and reliable strength retention in sub‑zero environments. It is widely used in LNG storage tanks, low‑temperature reactors, and cryogenic process equipment requiring consistent mechanical performance and long‑term structural integrity.
Chemical Composition

C	Mn	P	S	Si	Ni
≤ 0.17	0.40–0.70	≤ 0.025	≤ 0.025	0.15–0.30	3.25–3.75

 
Mechanical Properties

Property	Yield Strength	Tensile Strength	Elongation	Impact Energy
Requirement	≥250 MPa	485–620MPa	≥ 22%	Excellent low‑temperature performance (per ASTM A203 requirements)

 
Dimensions

Thickness	3–150 mm
Width	1220–4200 mm
Length	5000–18000 mm
Supports custom cutting and shaping.

Stock & Processing
Regular stock for A203 Grade A
Cutting, drilling, welding, bending, machining
Custom dimensions available
Fast delivery for project orders
Global supply capability

Applications
LNG storage tanks
Low‑temperature pressure vessels
Cryogenic process equipment
Refrigeration and gas separation units
Welded components requiring nickel‑alloy toughness

Certification & Support
Complies with ASTM A203/A203M
EN 10204 3.1 / 3.2 available
Third‑party inspection: BV / LR / ABS / DNV / SGS
Technical support for material selection and fabrication