Puzzled?

[wolfdales36]

Recently I had received some rectangular duct work on my job, it was 30x12 duct 26 gauge.
I had called our shop to say that it was the wrong gauge, it should have been 24 gauge. They had said that this was smacna regulation. they had said that on low pressure duct 26 gauge is acceptable up to 30".
from what I remember 26 gauge is only acceptable from 2" to 18", 24 gauge from 18" to 32"
I had asked them to fax me this information .
So my question is , has the smacna on our gauges been updated over the last 15 years?
If you can please reply to my question I would very much appreciate it.

Many Thanks,

[Diceman]

Not a union sheet metal worker but 26 gage looks good to me too. 24 gage over 18" that sounds like overkill, especially with the price of steel these days.

[twcpipes]

26 gauge can be acceptible when it is "cross-broken" especially up at the larger sizes and/or higher static presures.