What is ASTM A490 standard bolt?

ASTM A490 and ASTM A490M are ASTM international standards for heavy-duty structural bolts made from alloy steel. ASTM is an international standards organization that develops and publishes technical standards for structural bolts, alloy steel, and heat treatment. ASTM A490 bolts have a minimum tensile strength of 150 ksi. In metric terms, this standard is equivalent to a 10.9 high-strength high-strength bolt for the structural steel industry. In 2016, specifications A325 and A490 were officially withdrawn by ASTM and replaced by ASTM F3125. Heavy-duty hexagonal structural bolts A325 and A490 are now grades according to the new F3125 specification.


ASTM A490 bolts application

The application and geometry of these bolts is the same as that of the A325, but manufactured to a higher strength. The international standards are made according to the same digital degrees as ASTM A354 BD levels. As noted above, the grade system is implemented according to the same digital system of degrees as the ASTM F568M 10.9 property class. In addition, unlike other bolts, ASTN A490 bolts are not coated by hot dipping, mechanical deposition or electroplating. Because these bolts are made of metal rather than carbon steel, which has better rigidity and strength, so it is often used in building structures, its length is shorter to keep the work. ren do not from the connection. When electroplating or hot-dip galvanizing it creates a danger of deformation of the Hydrogen. ASTM has agreed to approve A490 coatings with different aluminum coatings/corrosion protection according to ASTM F 1136 Grade 3, and is known as coated dacromet.


ASTM A490 bolt specifications

The ASTM A490 specification includes two grades of bolts tempered from high-strength alloy steel instead of high-tensile medium carcon steel. There are 2 versions of this specification; ASTM A490 covers high-strength bolts for inch sizes and A490M for metric sizes. ASTM A490 includes 2 grades: Type 1 and Type 3, later known as weathered steel . Type 2 was recalled in 2002. Bolts to this specification are manufactured from ½” to 1-1/2” in Inch and from M12 to M 36 in metric.
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Chemical composition of bolt A490

Ingredient Type 1 (%) Type 3 (%)
Carbon 0.20 – 0.53 (less than 3/4″) 0.30 – 0.48 (less than 1-3/8″)
0.30-0.53 ( less than 3/4″) 0.35 – 0.53 ( use for 1-1/2″)
Manganese – min 0.40
Phosphorus – max 0.035 0.040
Sulfur – max 0.040 0.040
Copper 0.20 – 0.60
Crom – min 0.45
Niken – min 0.20
Molypden – min 0.15

Bolt mechanical properties ASTM A490

Nominal length Tensile strength
(min – ksi)
Yield strength
(min – ksi)
(min -%)
(min – %)
1/2″ to 1-1/2″ 150 – 173 130 14 40

Bolt Hardness ASTM A490

Bolt size Bolt length
Briell Rockwell C
min max min min
1/2″ – 1″ Under 2D 311 352 33 39
1/2″ – 1 2D or more 352 39
1-1/8″ – 1-1/2″ less than 3D 311 352 33 39
1-1/8″ – 1-1/2″ 3D or more 352 39