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Hollo bolts

Hollo bolts

Hollo bolts

We have a Two storey residential structure. Client mandates steel frame. Modular in nature - frames butted up one to the other, creating redundancy. Not a public building etc.
Rather than design specific connector (which is quite intricate) it has been suggested to use Hollo bolts. The problem being solved is that this will reduce the interference of bolt heads and nuts on one side of the section enabling panels and so on to be placed - having nuts and bolt heads obstruct would result in much much additional design work.

Is it allowed under ASCE to use such bolts?

Designer, Specifier (I don't regulate anything despite what my profile says)

RE: Hollo bolts

Do you mean can you use the right hand configuration in your attachment?
If so, I sure hope the code bans that? Its not a good configuration.

RE: Hollo bolts

The STI had a recent webinar on the use of Hollo type bolts. Their site also has a fair amount of information on the use of through bolts with HSS. With through bolts you have to be careful that you don't collapse the tube wall. and if the tension is not there, the nuts can 'work their way off'... I use threadlocker.

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


RE: Hollo bolts

Your picture doesn't seem to be related to your problem?

RE: Hollo bolts

He's using Hollo bolts in the LH image, and through bolts in the RH image.

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


RE: Hollo bolts

Ok, I see the Hollo bolt is a blind fastener system.

RE: Hollo bolts

"Rather than design specific connector...."

From this and your other post on hand tightening fasteners I get the impression you are buying these modular framing units.
The seller/manufacturer should should have plenty of technical info including details on approved fasteners etc.

I can envision designs where each of your provided fastening details could be OK, or problematic.

This flavor of hollow bolt needs torquing, and I did not see what the allowable hole clearances are.


I did not see Proper hole prep, alignment and deburring amentioned. Holes site drilled in place can have burrs and deformation defects that can prevent proper seating of the bolted components.
The modular framing units/components supplier should have these requirements. The installation team needs to know what the requirements are too.

RE: Hollo bolts

ASCE doesn't regulate the use of fasteners, so the answer to your question is null.

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