Old metal joist type, need help identifying from photo, Cast Iron?
Old metal joist type, need help identifying from photo, Cast Iron?
(OP)
Hello All,
See attached photos of metal joist/rafters, vintage is 1942 or earlier, they appear when you look very close to be cast iron. 24ft span, supporting roof. "T" shaped top and bottom chords with bar shaped web lacing. There are no welds visible at the intersections of the the web lacing. Adjacent larger steel beam and column framing is clearly stamped with Bethlehem Steel. The Bethlehem Steel catalog from that period doesn't have any open web members like this and the joist don't have any identifiable markings. Any idea what they may be?
See attached photos of metal joist/rafters, vintage is 1942 or earlier, they appear when you look very close to be cast iron. 24ft span, supporting roof. "T" shaped top and bottom chords with bar shaped web lacing. There are no welds visible at the intersections of the the web lacing. Adjacent larger steel beam and column framing is clearly stamped with Bethlehem Steel. The Bethlehem Steel catalog from that period doesn't have any open web members like this and the joist don't have any identifiable markings. Any idea what they may be?






RE: Old metal joist type, need help identifying from photo, Cast Iron?
RE: Old metal joist type, need help identifying from photo, Cast Iron?
Here is a reference - look at Figure 24
http://www.structuremag.org/wp-content/uploads/201...
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RE: Old metal joist type, need help identifying from photo, Cast Iron?
I have seen these types of joists or trusses before and suspect they are from the 20's or 30's. I would guess that these were before the days of SJI standards and most likely was a proprioritary design.
Unless you can find some load tables or a documented capacity, you most likely will have to fully measure up all steel members, welds, etc. and do a complete structural analysis of the truss for its capacity.
RE: Old metal joist type, need help identifying from photo, Cast Iron?
These come from SlideRuleEra's website found here where you can download the entire book: http://www.slideruleera.net/structural-steel-handb...
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RE: Old metal joist type, need help identifying from photo, Cast Iron?
RE: Old metal joist type, need help identifying from photo, Cast Iron?
The original material just _has_ to be mild steel for that to happen without fracture.
Mike Halloran
Pembroke Pines, FL, USA
RE: Old metal joist type, need help identifying from photo, Cast Iron?
Yes, it was a hot rolling process.
RE: Old metal joist type, need help identifying from photo, Cast Iron?
RE: Old metal joist type, need help identifying from photo, Cast Iron?