hardened washers , a-325 bolt connections

[scherry]

I have read the sentence several times and believe I understand it but...Section 7.c.5 asd, green book, specification for structural joints using astm A325... What EXACTLY is meant by an outer ply? Instinctively I think know, but it is going to cost someone money if my instint is wrong. Reason for this requirement when hardened washers are not usually required for a-325 unless they are fricion type connection (with a few other caveats under this same section ofthe spec)???

thanks!

 

[ajh1]

Think of a column splice where there is a splice plate on both the inside and outside of each column flange. The splice plates are outer plys, the column flange itself is an inner ply. What the RCSC spec is saying is that if you have an oversize hole or a short slotted hole in the splice plates, then you would need a hardened washer. An oversize or short slotted hole in the column flange would be okay per this rule.
I would recommend that you download the latest version of the RCSC spec for more information. That can be done from the RCSC web site,

http://www.boltcouncil.org

 

[scherry]

ok, that makes sense, and I WILL download the latest spec - thanks for the info. but if I have, say, a clip angle connection to the top of a tube steel column, and to the flange of a beam. the column is not to take loads from the beam above, but is stabilized by the clips at the top. (one clip each of two opposite sides. you can slot either the clips or the tube.I would tend to slot the clips since they are easier to do. In that case i need hardened washers because the clips are the outer plies, right? but if I were to decide to slot the tube steel instead, i would not need hardened washers? Which makes sense, now that i have written it, but i am not sure i would have them slot the tube to save the washers! thanks again for the link to the new spec.