High tensile bolts circa mid-1950s
High tensile bolts circa mid-1950s
(OP)
I'm working on a renovation project of a structural steel building constructed in the mid-1950s.
The plans call for 3/4" diameter "high tensile" bolts. Anybody know how I can figure out the capacity? Does this correspond to A325 properties of present?
The plans call for 3/4" diameter "high tensile" bolts. Anybody know how I can figure out the capacity? Does this correspond to A325 properties of present?






RE: High tensile bolts circa mid-1950s
Is there any reason why I can't use the current capacities for these bolts?
RE: High tensile bolts circa mid-1950s
RE: High tensile bolts circa mid-1950s
RE: High tensile bolts circa mid-1950s
RE: High tensile bolts circa mid-1950s
http://preserve.lehigh.edu/cgi/viewcontent.cgi?art...
For your project, I would suggest performing the calcs as if ALL the fasteners were rivets.
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RE: High tensile bolts circa mid-1950s
RE: High tensile bolts circa mid-1950s
Those nuts do not look light but I don't remember the use of square nuts. There is a possibility that they were made that way to distinguish them. Unfortunately, you cant rely on that. If the bolt heads can be confirmed as A325 from the other side, you might be able to use the modern bearing capacity since they are not partnered with rivets in the same connection, i.e. clip to supporting beam are all bolts, clip to supported beam are all rivets.
The paint job is in remarkable shape. If it hasn't been repainted, it might be red lead.
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin
RE: High tensile bolts circa mid-1950s
It looks like 15 ksi is the design shear stress I should use for rivets.
Does anyone how know difficult it is to remove rivets? I may need to rehab or replace some connections.
RE: High tensile bolts circa mid-1950s
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin
RE: High tensile bolts circa mid-1950s
1. The steel members could be damaged by the torch.
2. The paint is likely lead based, so fumes from cutting are an issue.
Perhaps adding welds would be another way to repair, without removing rivets, but then the fumes issue comes up again.
Looks like access to the beams is going to be a challenge if you have to do anything to them.
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