"GRIP" For bolted connection. 4

[Gymmeh]

I was asked if I knew anything about “Grip” of a bolted connection to a C-Channel.
I have always known the term to indicate the thickness of engaged material related to length along the bolt.

My boss has a really old book which shows the “Grip” to be the correct location to put a hole in the flange of a beam.

Everything I Google relating to grip, results in bolt grip.

Is my boss’s book correct and/or obsolete?

Is there another term used to indicate the proper location of a hole through a flange?

Thanks

 

[MintJulep]

My understanding is the same as yours.

Grip is defined in ASME B18.12 Glossary of Terms for Mechanical Fasteners

Grip: a term normally associated with structural bolting, the grip is the thickness of material or parts that the fastener is designed to secure when assembled.

 

[civilperson]

Gage is the location of bolt hole.

 

[Gymmeh]

civil,
do you have a referance for the term Gage?

Mint, execellent

Thank you both.

I will try to get my hands on the book to post the title, but i just got two more projects dumped on my desk so I am a little swamped, so it might take me a day.

 

[Gymmeh]

The Book with "Grip" in it is Manual of Steel Construction 6th Edition. by Stupp Bros. Bridge & Iron Co.

its got a nice AISC seal on the cover. Copyright 1963

 

[drawoh]

Gymmeh,

I have heard the term "grip" used to describe the unthreaded length of an AN (aircraft) bolt. I was also told that the bolt had to be long enough that the threaded portion was entirely outside the hole.

JHG

 

[Gymmeh]

drawoh,
yes, I agree with you.

I think I figured it out. The book does not show it clearly, at the bottem of the page is a note about finding the Gage location.

Basically it implies that Grip is the average flange thickness at the Gage location.

 

[Dinosaur]

That makes more sense to me because channels and S shapes have a notable taper in the flange, so the "reported grip" might need clarification. Grip is the distance from the inside of the head to the face of the nut in the snugged connection. Gage is the transverse location or spacing of fasteners. The idea of threads in the hole is something that determines if we have a type N or type X bolt (threads iNcluded in the shear plane -or- threads eXcluded from the shear plane). The type X bolt has a higher allowable but requires the outside plies to be fairly thick. The AISC Manual of Steel Construction spells this all out.

 

[Gymmeh]

Some good info here,

you all get stars!

Thanks

 

[DG72]

I have alwasys taken the grip length to be the distance from "1/2 nut to 1/2 nut".

 

[HeviiGuy]

I have alwasys taken the grip length to be the distance from "1/2 nut to 1/2 nut".

Yup: There's still a bit of confusion surrounding this one. The above definition is actually "effective length". That is, effective length of a stud in a through-hole. The effective length of bolts and studs fitted into blind holes is different still.

Ciao,

HevïGuy

http://www.heviitech.com

 

[MMR Advisor]

I found a wonderful resource for bolt information that I use a bit. In addition to bolt design topics, it also discusses techniques for tightening, pre-loading, double nutting, etc. Decent video and animations as well. It generally refers to UK standards vs ASTM and SAE, but the same physics still apply.

http://www.boltscience.com/