Anchor Bolt Hole Tolerances AISC 14-2

[Veer007]

Hey guys,
I saw a table from AISC, Which shows Max hole dia. but seems too large (1" 13/16), so is it better to use 1 1/2" edge distance for 1" dia anchor rod as I have only 9/16" from the edge of the hole to the edge of the plate?

Thanks in advance!!

 

[JLNJ]

It depends on what your anchors are doing. If they are just holding up the column during erection, then the edge distance probably doesn't matter much.

If you are using welded washers to transmit any shear you have, then the size of the bolt hole and the edge distance isn't critical; however, those small edge distances look odd when fabricated. I recommend increasing it to 2" just for this fact.

If you want the bolts to resist shear, then consider using holes smaller than the max. I often use smaller anchor rod holes (smaller than the AISC maximum recommendation) in base plates where I have some shear to transmit. I make the foundation contractor aware of this and make it obvious on the drawing since it's the normal foundation and anchor bolt setting tolerances which are the real culprit here.

 

[Veer007]

.

Thanks in advance!!

 

[r13]

This table is the recommended "maximum" hole size, not the recommended size. For 1" bolt, you can use standard bolt hole 1 1/16", and any size in between the standard and the maximum size.

 

[RWW0002]

For 1" bolt, you can use standard bolt hole 1 1/16", and any size in between the standard and the maximum size.

1 1/16 for 1" bolt! - I hope a field fix will work for these anchors (epoxy set or similar) because you will end up needing to issue a fix when these anchors are mis-set (or I should say set within the accepted tolerance for anchors in concrete and still don't fit..)

While I agree that the table is intended to be maximum hole sizes I would not recommend using 1/16" oversize holes in a base plate unless you want the concrete contractor to cry foul on construcability.

Similar to JLNJ, I have justified smaller holes than max recommended, but never below 5/16" oversize unless absolutely necessary. The 5/16" oversize holes and standard USS washers similar to older editions of the steel manual can be justified with footnote 3 in the table above.

 

[r13]

RWW,

Thanks for picking it out. Yes, you can but shouldn't be that tight (1 1/16" hole for 1" bolt). It just to indicate the range of hole size we can chose.

 

[dik]

Check and see what the project tolerances are, too if you've given them a 1/16" tolerance for the Anchor rods, and the column locations are +/- 1/4"... you may have a problem that is not the contractors. Also, I always spec weldable anchor rods... typically Grade 55 S1... I typically use 1/4" for all anchor rods... almost never have ones bigger than 1-1/2"

Dik