On Thu, 5 Oct 2017 15:56:04 -0700 (PDT), Christopher Tidy
wrote:

I've been looking at a few welded structures made from tubular steel and galvanised. They often include open holes (see pictures below). Anyone know why? I could make a few guesses but I'm not certain.

https://www.flickr.com/photos/138493...posted-public/
https://www.flickr.com/photos/138493...posted-public/

Chris
https://www.galvanizeit.org/design-a...g-and-drainage