When fabricating cut out blocks and forming blocks do you factor in the radius to the measurements? For example, if I was making a 12 inch square form with a 1 inch flange would my cut out form be 13 inches or would I add for the radius? The construction standards state you would add delta (change) squaredsquared but I'm not sure what that means.

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It would be somewhere between 12 and 13 inches, close to 13 but not quite, actually.

To get the 1 inch flange you have to take into account the bend portion itself.

I have attached a spreadsheet that calculates the numbers for you (in mm not inches).

I have also attached Zenith's Construction Standards.

On page CS #301 (18 of 42) it gives a simplified explanation of what is going on.

There is an explanation in the spreadsheet also.

Hope this helps,


Immensely helpful! The excel calculator is fantastic...thank you for sharing it!


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