In article , Christian
McArdle wrote:
Also, I bet the 76x76x12 RSJ is probably not much more than half the
127x75x13 UB in weight and cost.

The last number is the nominal weight: one is 12kg/m run, the second
13kg. So I'd expect them to cost about the same. Availability of RSJ
section might be an issue too, although they are listed in the 'Blue
Book'

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