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Flat Headed High Strength Bolts 1

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dik

Structural
Apr 13, 2001
25,675
Can anyone recommend a type of high strength Fu > 60ksi, with a flat head that can be countersunk Bolt size is 1/2" dia... UNC thread.

Thanks, Dik

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

-Dik
 
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Exactly... I looked through Portland Bold, and couldn't find anything Thanks very much.

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

-Dik
 
What are you using them for? The last time I had seen countersunk bolts that big they were an issue. They kept coming loose due to the traffic vibration.
 
I have to anchor some guardrail posts to 3" oak planking treads with 4x4 base plates... BAR 3/8x2 posts, using through bolts and steel backer plate. Use locktite to prevent loosening. Bolt loads are high... and dap the baseplates into the oak with flat head screws... I searched Portland looking for flat head bolts, not countersunk bolts. Again, thanks.

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

-Dik
 
Holo-Krome makes flat head cap screws that meet ASTM F835, but cautions against using them for high strength applications. Can you fit a counterbore and a socket head cap screw in?

flathead1_wo74nt.jpg
 
Probably not enough thickness... the 1/2 fasteners fit into a 3/8 plate and the entire assembly is 'dapped' into 3" thick oak treads of the stair. The baseplate is so small, tension loads in the bolts are high and secured by using 'through bolts'.

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

-Dik
 
FHSCS are not available in hot-dipped galvanized due to hydrogen embrittlement issues - same issues with HDG as Grade A490 bolts. You will probably end up with stainless fasteners if you need corrosion protection.
 
Thanks... I don't know what the finishes are yet... but, it's interior.

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

-Dik
 
In typical Eng-Tips fashion, instead of answering the question it would be nice to know the big picture and make suggestions on that ...
 
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