ASTM A490 Grades

A490 Types

TYPE 1 - Medium carbon and alloy steel.

TYPE 2 - Withdrawn in 2002.

TYPE 3 - Weathering steel.

M - Metric A490.


A490 Connection Types
SC Slip critical connection.
N Bearing type connection with threads included in the shear plane.
X Bearing type connection with threads excluded from the shear plane.

A490 Mechanical Properties
Size Tensile, ksi Yield, ksi Elong. %, min RA %, min
1/2 - 1-1/2 150 - 173 130 14 40

A490 Chemical Properties
Type 1 Bolts
Element Sizes 1/2 to 1-3/8 Size 1-1/2
Carbon, max 0.30 - 0.48% 0.35 - 0.53%
Phosphorus, max 0.04% 0.04%
Sulfur, max 0.04% 0.04%
Alloying Elements * *

* Steel, as defined by the American Iron and Steel Institute, shall be considered to be alloy when the maximum range given for the content of alloying elements exceeds one of more of the following limits: Manganese, 1.65%, silicon, 0.60%, copper, 0.60%, or in which a definite range or a minimum quantity of any of the following elements is specified or required within the limits of the recognized field of constructional alloy steels: aluminum, chromium up to 3.99%, cobalt, columbium, molybdenum, nickel, titanium, tungsten, vanadium, zirconium or any other alloying elements added to obtain a desired alloying effect.

Type 3 Bolts
Element Sizes 1/2 to 3/4 Size above 3/4
Carbon 0.20 - 0.53% 0.30 - 0.53%
Manganese, min 0.40% 0.40%
Phosphorus, max 0.04% 0.04%
Sulfur, max 0.04% 0.04%
Copper 0.20 - 0.60% 0.20 - 0.60%
Chromium, min 0.45% 0.45%
Nickel, min 0.20% 0.20%
or - -
Molybdenum, min 0.15% 0.15%

A490 Recommended Hardware
Nuts Washers
Type 1 Type 3 Type 1 Type 3
A563DH A563DH3 F436-1 F436-3

Note: Nuts conforming to A194 Grade 2H are a suitable substitute for use with A490 heavy hex structural bolts. Follow the link for an ASTM A563 Nut Compatibility Chart.


All information derived from globally recognized specifications, subject to change, user discretion is advised.