Answer:
The governing ratio for thin walled cylinders is 10 if you use the radius. So if you divide the cylinder´s radius by its thickness and your result is more than 10, then you can use the thin walled cylinder stress formulas, in other words:
- if [tex]\frac{radius}{thickness} >10[/tex] then you have a thin walled cylinder
or using the diameter:
- if [tex]\frac{diameter}{thickness} >20[/tex] then you have a thin walled cylinder
