Torsional constant - solid rectangle 1

[LR11]

Has anyone come across the formula for the torsional constant of a solid rectangle.
The closest I've gotten is from this link:
[URL unfurl="true"]https://core.ac.uk/download/pdf/228624404.pdf[/url]
From page 7 onwards.

 

[r13]

Better deal, here is a calculator. Please let me know if b is wider than h is any different than h wider than b. Thanks. Link

 

[r13]

Check this out too.

 

[r13]

Reading for J and Ip, see the first answer, Link

 

[LR11]

Thanks r13, you're right in post #2.

 

[r13]

You are welcome. Both #1 and #2 can be used, as J is an approximation, the difference is small.