Mike, I need more infomation. My book shows a shear strenght for low alloy steel (SAE 950) at 45- 50,000 PSI. Many other factors figure into this equasion.
If you can explain the problem in more detail, I may be able to remedy it for you. You are working with more than simple shear strenght.
I did some more research and think I know part of the answer now. The project is a free standing perola. 4 (6x6) posts will support 4 rafters (2x10 x 18 feet). 2 rafters with a post sandwiched between them, the connection to the posts would be with 4 (1/2 x 10 inch) galvanized bolts. These rafter will support 18 lintels (2x8 x 14 feet) placed perpendicular to the rafters.
What I have found is based on considering deck building where the dead load is considered to be 10 psf. Taking the area of the rafters and lintels, I come up with 252 square feet (18x14) x 10 psf = 2520 psf, then divide that total area by 4 since each post will share the load = means each post will have to support 630 psf.
With 630 psf how do you determine if 4 1/2 inch galvanized bolts will support it? Or is this number so small compared to the shear strength of these bolts that you don't even have to worry about it?
I would normally notch the top of each 6x6 so the rafter would sit on a ledge and then run the bolts through, but the homeowner is insisting on this design of no notches, just sandwiching the 6x6's between the rafters, so this is why I am trying to determine if this is going to be safe.
Can't find the shear pressure any where and I know I've got it.
This may help and Teetor can clarify it some more with his charts.
These are the most common bolts you will find.
Grade 2 bolts - no marks on the head is 1020 steel
Grade 5 bolts - 3 marks on the head is 1035 Hi Carbon steel
Unlike you will need anything this hard but,
Grade 8 bolts - 6 marks on the head - 1041 Hi Carbon steel 155,000 psi
Hex-Alloy bolts - 8 marks on the head - 180,000 psi
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