Inquiry: Use of 3/4" Ø Bolt for 4" Wide Beam 3

[Veer007]

Hey All,

Hope you are all good. I'm working on a beam-over-column connection with a 4" wide beam (W12x19). The beam has a 2 1/4" gauge, and I'm considering using 3/4" Ø bolts. Can you advise if this bolt size is suitable for this beam considering only the edge distance which is 7/8"? As J3.4 advises min. edge distance is 1" for 3/4"Ø bolts

Thank you for your assistance.

Thanks in advance!!

 

[DrZoidberWoop]

This is clearly spelled out in AISC Table J3.4. You can use smaller edge distances, which is fine, but will raise red flags during approval. You can also use edge distances smaller than the bolt diameter with explicit permission from the EOR.

The better option is to upsize to a W12x26 and use a reasonable gage. This happens all the time.

 

[XR250]

Why do you need a 3/4"ø bolt?

 

[Veer007]

Thanks, I am a Steel Detailer. I will verify this with EOR

.

There is a note saying use 3/4"Ø for connections U.N.O

Thanks in advance!!

 

[dik]

If the edge distance is too little for 3/4" fasteners, I would design the connection for 5/8 (if they work) with the exception that the EOR/Arch confirm. Occasionally happens... more often the fabricator is using 3/4" bolts when M20 are spec'd... Still ask EOR to confirm.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Sci3_Solo]

You may have an issue with bolts hitting the k region of the beam. If upsizing isn't an option, I'd consider weld it to column cap plate or weld a "base plate" on the bottom of the beam and bolt that instead.

Also, why is a W12x19 sitting on a column? Is there no perpendicular beam?

 

[XR250]

I imagine if you contact the EOR you will find the load on the bolts is pretty small and 1/2"Ø would work.
Not sure if 1/2" is a thing in the industrial steel fab industry though.

 

[RPGs]

I usually go down a bolt size. Lately I've been using 1/2" diameter A307 for smaller steel beam to column cap plates like this.

Not sure if 1/2" is a thing in the industrial steel fab industry though.

I've caught flak for specifying 1/2" diameter A325N bolts, as one client claimed they are not available (which doesn't make sense to me if I can find it for sale on google, but I guess I don't have the whole story).

 

[TLHS]

Man, dik, are people actually specifying M20 bolts in Canada for steel? I thought we basically stopped fighting the fight with bolt sizes. Even on fully metric drawings the exception for me is bolt sizes.

 

[Veer007]

Thanks for all your responses, If I should change it, still have an option to use a 5/8"Ø bolt size? just wonder because so many of you mention 1/2"Ø than 5/8"Ø bolt.

Thanks in advance!!

 

[dik]

I generally use 5/8 as my min A325 bolt... other than for stair treads, and sliding connections, I don't like A307s, either. One of my many personal quirks...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

My work for the last 3 years has been designing connections for metal fabricators. I'm on my 982 project (most are small, but have included a 6 storey building addition). I often encounter M20s, and I aske the EOR to confirm the use of M19s. Often the fabricator will use M19s, but I still ask for confirmation... for legal and liability reasons.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik