Difference between A517 Grade F and A517 Grade A steel plate

ASTM A517 Grade A is a high-strength, quenched and tempered alloy steel plate designed primarily for fusion-welded pressure vessels and boilers . It offers a minimum yield strength of 690 MPa (100 ksi) and a tensile strength range of 795-930 MPa (115-135 ksi), with a minimum elongation of 16% . Its chemical composition includes carbon (0.13-0.23%), manganese (0.74-1.20%), chromium (0.46-0.84%), and molybdenum (0.15-0.31%) . The maximum plate thickness for Grade A is 1.25 inches (32 mm). It is widely used in applications such as pressure vessels, penstocks, and hydraulic equipment where high strength-to-weight ratio is critical.

ASTM A517 Grade F is also a high-strength, quenched and tempered alloy steel plate under the same standard, sharing the same minimum yield strength of 690 MPa (100 ksi) and tensile strength of 115-135 ksi (795-930 MPa) . However, Grade F contains nickel (0.67-1.03%) and copper (0.15-0.50%) , along with vanadium (0.02-0.09%), which enhances its toughness, especially at low temperatures . The Charpy V-notch impact test temperature for Grade F can be specified as low as -46°C, offering superior low-temperature performance compared to Grade A. Its maximum thickness is 2.50 inches (65 mm) , allowing for thicker sections.

Both ASTM A517 Grade A and Grade F are high-strength quenched and tempered alloy steel plates with a minimum yield strength of 690 MPa, making them ideal for demanding pressure vessel applications . Their primary difference lies in chemical composition and resulting performance: Grade A is a general-purpose high-strength grade with moderate alloying, suitable for standard applications , while Grade F incorporates nickel and copper with vanadium, offering enhanced low-temperature toughness (testable down to -46°C) and a greater maximum thickness of 65 mm . Grade F is therefore preferred for more critical or colder service environments where both high strength and superior fracture resistance are required.

Chemical Composition

Mechanical Property