can 2-3/4" dia bolt row fit in W6 (6" depth) 1

[delagina]

I work in industrial and we typically use W8/C8 as minimum when bolted shear connection and 3/4" bolt is typically the minimum bolt size for steel structure.
But can 2-3/4" dia bolt row fit in W6 (6" depth) without issues with wrench clearance?

 

[SlideRuleEra]

Per AISC (9th Edition Manual of Steel Construction, Page 4-137) a "standard socket" for 3/4" high-strength bolts is 2 1/4" in diameter. Layout the proposed bolt pattern to see if it will work.

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[bridgebuster]

Per AISC 7th Edition, Page 4-26, W8 is the smallest section for a 2 row connection. AS SRE says lay it out; more than one way to tighten a bolt. One potential problem will be maintaining the minimum spacing between the bolts.

 

[TehMightyEngineer]

Any reason you're not using a welded connection?

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

https://www.facebook.com/AmericanConcrete/

 

[dhengr]

A “2-3/4" dia bolt” is a pretty large bolt in any case, but in a W6 beam or col...., really?

 

[KootK]

Is a spatial limitation driving the 6" depth choice? I'm sure that it's possible to get two bolts in there somehow (stagger etc) but it would be one of those situations where sacrificing convention probably costs more for everybody than just going with a deeper piece.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[dozer]

You will have to use less than the "standard" 3" spacing on the bolts but you should be able to squeeze them in. Remember, AISC will allow you to go down to 2.67 x nominal bolt diameter for the spacing.

 

[azcats]

If your load allows - A325 hardware is readily available in 1/2" and 5/8" sizes. A490 is hard to find in 1/2" though.

 

[TLHS]

I basically don't use anything smaller than an 8" beam if I'm bolting up, unless there's some huge cost difference or it's part of small load assembly where I could default to a smaller bolt size that 3/4".

You have to start looking at smaller bolts or non-standard arrangements below 8" depth.

 

[delagina]

I cannot field weld (long story). top of grating needs to match top of existing beam (long story).
3/4" dia bolt, standard minimum we use. can I use smaller? yes, but prefer not to.
even if I use W8 beam, existing beam is just 8" and I'm losing 1.25" depth because of grating.

maybe I should use 2 columns, 1 row of bolt.. instead of 2 rows, 1 column, no?

 

[WillisV]

Dap the end and put it on a seat.

 

[MotorCity]

It is possible to fit 2 bolts vertically within a W6, but we usually place them horizontally for ease of fabrication and erection.

 

[TehMightyEngineer]

3/4" dia bolt, standard minimum we use. can I use smaller? yes, but prefer not to.

Why? I'm all for standardizing bolts, welds, and member sizes to simplify things but this is a plenty good reason to just specify what you need.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

https://www.facebook.com/AmericanConcrete/

 

[dik]

Have you looked to see what the actual load transfer is? I'm surprised a single line of two bolts would likely transfer the load.

Dik

 

[KootK]

maybe I should use 2 columns, 1 row of bolt.. instead of 2 rows, 1 column, no?

I see that from fabricators a fair bit when they're trying to satisfy the two bolt minimum rule in pieces that, like this one, are too small to manage that conventionally. I'm fine with it for small loads so long as the angle is checked as essentially to independent plates cantilevered from their respective bolt groups. Fine for small loads which is usually the case.

Here are some other, more robust alternatives including switching to a 6" channel.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.