ASTM A490 (withdrawn and rolled into ASTM F3125)
A490. Alloy steel, quenched and tempered.
| Size range | Proof | Yield min | Tensile min | Core hardness |
|---|---|---|---|---|
| 1/2 in through 1-1/2 in | 120 ksi (827 MPa) | 130 ksi (896 MPa) | 150 ksi (1034 MPa) | Rockwell C33 to C38 |
Inch grades are published in ksi and metric classes in MPa. The other column on every row is a conversion at 1 ksi = 6.894757 MPa, rounded to the nearest whole unit - it is arithmetic on the published figure, not a second published figure.
Marked A490 on the head, with the manufacturer's identifier.
The specification stamped in full.
Count the radial lines and add two. That rule identifies exactly two grades - SAE Grade 5 with three lines and SAE Grade 8 with six - and it fails everywhere else. Grades 1, 2 and 4 carry no marking at all, so an unmarked head is not evidence of Grade 2; it is evidence of nothing, and unmarked hardware that meets no standard looks exactly the same. ASTM grades are stamped with the specification (A325, A490, BC, BD, 307A) rather than lines, and metric classes are stamped with the class number. Four marking systems share one bin.
Alloy steel, quenched and tempered. Structural steel connections needing more capacity than A325.
A490 carries a tensile MAXIMUM of 170 ksi as well as the 150 ksi minimum. A structural bolt that is too strong is a rejectable bolt.
A490 was withdrawn as a standalone specification and now sits in ASTM F3125 as Grade A490.
A490 bolts are not to be hot-dip galvanized; the hydrogen embrittlement risk at this strength is why. Check the current specification before ordering any coating.
Over 1/2 in through 1-1/2 in, ASTM A490 requires a minimum tensile strength of 150 ksi (1034 MPa), a minimum yield of 130 ksi (896 MPa) and a proof load of 120 ksi (827 MPa).
Marked A490 on the head, with the manufacturer's identifier.
Alloy steel, quenched and tempered. Structural steel connections needing more capacity than A325.
Twenty-two grades and classes: the SAE J429 inch grades, five ASTM specifications and the ISO 898-1 property classes. It is not every grade in circulation. Stainless classes (ISO 3506 A2 and A4, ASTM F593), the ASTM A193 and A320 high and low temperature grades, ASTM F1554 anchor rod grades and SAE grades 3, 5.1 and 8.1 are not carried here.
Dimensions are as defined by ASTM A490 (withdrawn and rolled into ASTM F3125). This site is an independent reference and is not affiliated with, endorsed by or approved by any standards body.
Every value on this page was cross-checked against 3 independent published sources:
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