What is the all thread rod equivalent for A325 and A490?

In 2015, ASTM created a new, all-inclusive specification F3125 to cover A325 and A490 bolts under the same specification.  There were many changes made to the specification, but it is still not acceptable to manufacture fully threaded rods in the A325 or A490 specifications.  The new F3125 specification states in section 4.1.3:

Bolts with thread lengths or dimensional requirements which differ from this specification may also be ordered under Specification A449 or A354.  Users should note that A449 and A354 are not exact equivalents to the structural grades in this specification.

Although a new specification has been introduced, the rules for manufacturing threaded rods remain the same.

Portland Bolt frequently receives inquiries from customers requesting all thread rod conforming to the A325 and A490 specifications.  It is a common misconception that these two grades can be manufactured in any configuration of fastener.  In fact, these two grades of fasteners can only be manufactured as heavy hex structural bolts.  Both specifications provide alternative specifications to use when other configurations of fasteners are needed.

The ASTM A325 specification states in section 1.5:

This specification is applicable to heavy hex structural bolts only.  For bolts of other configurations and thread lengths with similar mechanical properties, see Specification A449.

Grade Marking Specification Material and Treatment Nominal Size (In.) Mechanical Properties Hardness Rockwell
Proof Load Min (ksi) Yield Strength Min (ksi) Tensile Strength Min (ksi) Elong % Min [9] RA % Min [10] Min Max
ASTM A325 Type 1 A325 Type 1 Medium Carbon Steel, Q & T 12" - 1"
118" - 112"
85
74
92
81
120
105
14 35 C24
C19
C35
C31
ASTM A325 Type 3 A325 Type 3 Atmospheric Corrosion Resistant Steel, Q & T
ASTM A449 Type 1 A449 Type 1 Medium Carbon Steel, Q & T 14" - 1" 85 92 120 14 35 C25 C34
118" - 112" 74 81 105 C19 C30
158" - 3" 55 58 90 B91 B100
ASTM A449 Type 3 A449 Type 3 Weathering Steel, Q & T 14" - 1" 85 92 120 14 35 C25 C34
118" - 112" 74 81 105 C19 C30
158" - 3" 55 58 90 B91 B100

The ASTM A490 specification states in section 8.1.2:

The thread length shall not be changed from that specified in ASME B18.2.6 for heavy hex structural bolts.  Bolts requiring thread lengths other than those required by this specification shall be ordered under Specification A354 Grade BD.

Grade Marking Specification Material and Treatment Nominal Size (In.) Mechanical Properties Hardness Rockwell
Proof Load Min (ksi) Yield Strength Min (ksi) Tensile Strength Min (ksi) Elong % Min [9] RA % Min [10] Min Max
ASTM A490 Type 1 A490 Type 1 Medium Carbon Alloy Steel, Q & T 12" - 112" 120 130 150 min
173 max
14 40 C33 C38
ASTM A490 Type 3 A490 Type 3 Atmospheric Corrosion Resistant Steel, Q & T
ASTM A354 Grade BD A354 Grade BD [6] Medium Carbon Alloy Steel, Q & T 14" - 212" 120 130 150 14 40 C33 C39

The A449 and A354 Grade BD specifications are virtually identical in mechanical and chemical properties to the A325 and A490 specifications.  The biggest differences between the two groups of specifications is that the A449 and A354BD specs do not have any configuration limitations and also boast a larger diameter range, whereas the structural specifications only cover bolts from 1/2″ through 1-1/2” diameter. One note with regard to the A490 specification is that it requires magnetic particle testing, whereas A354 Grade BD does not.  Therefore, when ordering all thread rod to A354 Grade BD, if magnetic particle testing is required, it must be specified on the inquiry and purchase order.

If you have a project that requires fasteners with similar strength properties to A325 or A490 in odd configurations, give Portland Bolt a call.  We specialize in manufacturing nonstandard construction fasteners in the A449 and A354 Grade BD specifications.

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4 comments

    Hi Gents.
    We requested 1″ ASTM F3125 Grade A490 Structural heavy hex head bolts and we received A325M 8S DFC. They are the same?

    @Jorge- No, those items are not similar. F3125 grade A490 is a very high strength structural bolt with a 150ksi minimum tensile. An A325(M) bolt is also structural, but only has a 120ksi minimum tensile. They should not be substituted without proper authorization from the project engineer.

    HEY, I DON’T KNOW ANYTHING ABOUT ASTM A325. WE NEED TO PURCHASE
    1 PCS. – 2-1/4 RB X 20′ LONG.
    CAN WE STILL GET THIS MATERIAL……DID IT CHANGE ASTM F3125?

    PLEASE HELP!
    THANK YOU

    @Ronda- The A325 standard, and new F3125/A325 grade only covers bolts up to 1-1/2″ diameter, so larger material would need to be be sourced from a different grade. The new F3125/A325 specification is essentially the same as the old A325 standard, but they cover finished structural bolts, not raw round bar.

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