| Weld design | Section modulus of throat area of butt weld W [mm 3 , in 3 ] | |
| for full weld length | for load-bearing (active) weld length | |
| 
 |  |  | 
| 
 |  |  | 
| 
 |  |  | 
| 
 |  |  | 
| 
 |  | - | 
Meaning of used variables:
| D | tube outer diameter [mm, in] | 
| L | weld length [mm, in] | 
| s | thickness of thinner joined part [mm, in] |