| Specification | Pipe class | Longitudinal joint factor (E) | 
|---|---|---|
| ASTM A 53/A53M | Seamless | 1.00 | 
| Electric resistance welded | 1.00 | |
| Furnace butt welded | .60 | |
| ASTM A 106 | Seamless | 1.00 | 
| ASTM A 333/A 333M | Seamless | 1.00 | 
| 
                     
                                
                                    Code of Federal Regulations
                                
                                52
                             
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| Electric resistance welded | 1.00 | |
| ASTM A 381 | Double submerged arc welded | 1.00 | 
| ASTM A 671 | Electric-fusion-welded | 1.00 | 
| ASTM A 672 | Electric-fusion-welded | 1.00 | 
| ASTM A 691 | Electric-fusion-welded | 1.00 | 
| API 5 L | Seamless | 1.00 | 
| Electric resistance welded | 1.00 | |
| Electric flash welded | 1.00 | |
| Submerged arc welded | 1.00 | |
| Furnace butt welded | .60 | |
| Other | Pipe over 4 inches (102 millimeters) | .80 | 
| Other | Pipe 4 inches (102 millimeters) or less | .60 |