Can A325 and A490 structural bolts be supplied with fine thread?

No. The specification calls out that those bolts must be Unified National Coarse thread and have class 2A tolerances.

The F3125/F3125M specification reads:

4.2 Threads:

4.2.1 Uncoated bolt threads shall be as specified in Table 1.

4.2.2 Coated bolts shall have threads meeting Table 1 requirements before coating.


Thread Fit, ASME 120 ksi Min Tensile Strength


150 ksi Min Tensile Strength


Type 1 Type 3 Type 1 Type 3
B1.1 UNC 2A B1.1 UNC 2A B1.1 UNC 2A B1.1 UNC 2A
Written ,

Leave a Reply

Your email address will not be published. Required fields are marked *