Countersunk Bolt Steel Plate

[tclat]

Hi,

I'm working on a connection detail for a curtain wall. The window manufacturer wants to use 3/8" dia countersunk bolts (tapered head)in a 1/2" thick plate. The bolts will have about 1.2kip factored tension. Can someone point me to a reference for checking the pullout capacity?

Thanks.

 

[MotorCity]

Pullout from what? There is no "Pullout" check for steel, so I am assuming you are talking about concrete. See ACI 318 Appendix D.

 

[CANPRO]

Do you mean the pullover capacity of the 1/2" plate? Not sure how to come up with a value for that, however, there are published values for allowable pullover for self-tapping screws. See link below to the ESR report for Hilti's self-tapping screw. Looks like you could almost get the capacity you need out of a self-tapping screw (0.433" diameter head) and 10 Ga steel (0.135" thick). I would think that your condition would be significantly stronger - larger diameter head and what should be thicker steel (accounting for countersunk portion).

http://www.icc-es.org/Reports/pdf_files/ESR-2196.pdf

 

[Tmoose]

http://www.unbrako.com/images/downloads/engguide.pdf

The Flat head/countersunk torque spec is about 1/2 that of regular SHCS. I think the reduction must mostly be based on the head strength.
Approximate FH clamp force would be over 3000 lbs.

http://www.spaenaur.com/pdf/sectionD/D48.pdf

 

[SwinnyGG]

The Flat head/countersunk torque spec is about 1/2 that of regular SHCS. I think the reduction must mostly be based on the head strength.
Approximate FH clamp force would be over 3000 lbs.

The recommended installation torque is reduced for a FHCS because the tool size is smaller- a 3/8" FHCS has a 7/32" hex, while a 3/8" SHCS has a 5/16" hex. Big difference.

From experience, a FHCS will fail in tension way, way before the head will pull out of any steel or aluminum part I've ever used.

 

[tclat]

Yes....pull-over strength is what I'm looking for.

Thanks CANPRO.....I can buy that logic, using the tables for weaker materials.

Based on comments from Tmoose and jgKRI, my loads seem small and should be ok.