Does the ASTM Require a Rotational Capacity Test for A490 Structural Bolts?

No, ASTM does not require a rotational capacity test for A490 structural bolts. The reason for this is that the purpose of the rotational capacity test per ASTM is to evaluate the presence and efficiency of the lubricant used in a bolt and nut combination. Lubrication is used with galvanized bolts since there is additional friction resulting from the galvanizing of the bolt threads. Therefore, ASTM requires that a rotational capacity test be performed on galvanized A325 structural bolts and not plain finish A325 Structural Bolts. Since A490 heavy hex structural bolts cannot be galvanized, ASTM does not require a rotational capacity test be performed on them.

Update: The newer F3125 structural bolt standard, which combines six bolting standards, A325, A325M, A490, A490M, F1852, and F2280 does layout procedures for rotational capacity testing on A490 bolts. However, the F3125 standard only requires this testing be performed when requested.

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6 comments

    Sir,

    I have ASTM A490 bolts its have small rust on the threaded part, can i use lubricant for remove the rust and this bolt can i use friction joint.

    Please advise

    @Ramesh- Normally a bit of easily removable surface rust is not concerning. However, we would recommend that you get approval from the project engineer just in case.

    Is lubrication required for the ROCAP tests on A325 Galvanized Bolts? Also, do we still need to do the Sampling as required by RCSC on A325 Galvanized Bolts? If so, do we use Lubrication on the A325 Glavanized Bolts?

    @Dennis- The A563DH nuts that are required for use with A325 galvanized bolts will have a wax lubricant already on them. If additional wax is needed, I believe that is acceptable, but if extra lubrication is used on the rocap test, then it must be used for installation as well. The sampling plan in the RCSC is three assemblies tested in the field, which differs a little from the sampling plan ASTM F1470 that most manufacturers follow when testing in their own facility.

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