ASTM A490 - Standard Specification for Structural Heavy Hex Bolts, Alloy Steel, Heat Treated, 150 ksi Minimum Tensile Strength with Type 1 & Type 3 Weathering Steel Bolting Class
This specification covers two types of bolting grades quenched and tempered, manufactured from high strength alloy steel. ASTM A490 Bolts are intended for used in structural connections similar to ASTM A325/A325M but being produced from alloy steel instead of medium carbon steel, possed high tensile strength. There are two versions of this specification; ASTM A490 covering imperial sized high tensile bolting and A490M for metric sized bolts. ASTM A490 covers two grades Type 1 & Type 3, the later being weathering steel. Type 2 was withdrawn in 2002. Bolts under this specification are manufactured from 1/2" to 1-1/2" in imperial & from M12 to M36 in metric sizes. Ferrobend is a outstandig performer in providing ASTM A490 Type 1 & Type 3 weathering steel bolts with zinc, cadmium or dacromet coatings with EN 10204 Type 3.1 Certification.
ASTM A490 Bolt Grades
ASTM A490 Chemical Composition
| Element |
Type 1 % |
Type 3 % |
| Carbon |
0.20 - 0.53 (3/4" and smaller) |
0.30 - 0.48 (sizes through 1-3/8") |
| 0.30 - 0.53 (larger than 3/4") |
0.35 - 0.53 (for 1-1/2") |
| Manganese, min |
0.400 |
-- |
| Phosphorus, max |
0.035 |
0.040 |
| Sulfur, max |
0.040 |
0.040 |
| Copper |
0.20 - 0.60 |
-- |
| Chromium, min |
0.45 |
-- |
| Nickel, min |
0.20 |
-- |
| Molybdenum, min |
0.15 |
-- |
ASTM A490 Mechanical Properties
| Nominal Diameter, inch |
Tensile Strength, min, ksi |
Yield Strength, min, ksi |
Elongation in 4D, min, % |
Reduction in Area, min, % |
| 1/2" to 1-1/2", Inclusive |
150 - 173 |
130 |
14 |
40 |
ASTM A490 Hardness Requirements
| Bolt Size, mm |
Bolt Length*, mm |
Brinell |
Rockwell C |
| min |
max |
min |
max |
| 1/2" to 1", inclusive |
Less than 2D* |
311 |
352 |
33 |
39 |
| 1/2" to 1", inclusive |
2D and over |
-- |
352 |
-- |
39 |
| 1-1/8" to 1-1/2", inclusive |
Less than 3D |
311 |
352 |
33 |
39 |
| 1-1/8" to 1-1/2", inclusive |
3D and over |
-- |
352 |
-- |
39 |
Note* : Heavy Hex Structural Bolts 1" and smaller and shorter than 2D are subject only to minimum and maximum hardness. Heavy hex structural bolts larger than 1" through 1-1/2" inclusive in diameter and shorter than 3D are subject only to minimum and maximum hardness.
ASTM A490 Heat Treatment
Type 1 and Type 3 bolts shall be heat treated by quenching in oil from the austenitic temperature and then tempered by reheating to a temperature of not less then 800°F.
ASTM A490 Bolt Marking
ASTM A490 Recommended Nuts & Washers