Unknown Iron shape "ROD. PN-16"

[souzastr]

I have encountered an existing beam in a residence built in the 1960's with a rather odd steel (or probably iron) shape. The member is 6 1/4" deep, with 2 13/16" wide flanges. The flanges are approximately 1/4" thick. On the side of the web is stamped "ROD. PN-16". Does anyone know what this shape is? I'd like to determine the section properties as well as material properties.

 

[racookpe1978]

I'm going to (politely) disagree with with you and claim that the imprint is more likely "ROD PN 6". Who is ROD? Don't know. 8<)

The vertical support is (almost always) a simple 4" "dumb" pipe made of unrated steel in the cellar/basement. (Like mine, for example.) Scaling, that also indicates the wide flange is a 6 inch nominal size.

Put a caliper (a simple plastic one or small one from Sears - no need for thousandths of an inch calibrated accuracy!) on the (1) beam flange width, (2) beam flange thickness (near midpoint, not edge) and (3) actual beam depth.

You will be able to find the actual properties from a table of nominal sizes when those three dim's match. if any disagreement, throw out flange thickness - it is most likely to be off.

DON'T assume a high-grade steel!

 

[JStephen]

Seems like I have seen beams (and/or railroad rails) where the stuff rolled into them like that related to the manufacturer and date, and not the size. So you might eventually decipher the inscription and still not know what size beam it is.

A cheap dial or digital caliper or micrometer would get you the flange thickness pretty readily, and it wouldn't be too hard to calculate pertinent properties from that.

Looking around some online, I'm not seeing anything of those dimensions.

 

[JStephen]

Here, I find a "160" metric beam that is about the right overall dimensions, though it works out to a 3/8" flange. But could that 16 be 16cm = 6.29"?

http://sketchup.engineeringtoolbox.com/ipn-european-i-beams-c_116.html

(I don't know anything about this beam series, so I have no idea if they existed in 1960, or how common they would have been in the US.)

 

[souzastr]

I believe that you're right JStephen. It does appear to be a "European Standard Beam" (IPN). It has tapered interior flange faces. Also, based on some welding that I've seen done to this beam, I think that it is steel. Does anyone know what type of steel I could expect a 1960's era IPN to be made of. I may try to convince the owner to submit a coupon to a testing lab, but having an expectation would be good. Did European standards dictate 36ksi steel?