Fillet Clearance for Electric-Arc Welded Full Base Studs
When a stud is end-welded, a fillet forms around its base with the fillet dimensions being closely controlled by the design of the ferrule used. Since the diameter of the fillet is generally larger than the diameter of the stud, some consideration is required in the design of mating parts. Counterbore and countersink methods are commonly used. Dimensions will vary with studs and ferrules. Additional methods of accommodating fillet include oversized clearance holes, use of gasket material around the fillet or use of a dog type construction.
| Stud Size (In.) | Counter Bore (In.) | Counter Bore (In.) | 90° Counter Sink (In.) |
| A | B | C | |
| 1/4" | 0.437 | 0.125 | 0.125 |
| 5/16" | 0.500 | 0.125 | 0.125 |
| 3/8" | 0.593 | 0.125 | 0.125 |
| 7/16" | 0.696 | 0.187 | 0.125 |
| 1/2" | 0.750 | 0.187 | 0.187 |
| 5/8" | 0.875 | 0.218 | 0.187 |
| 3/4" | 1.125 | 0.312 | 0.187 |
A. Oversized clearance hole
B. Gasket material
C. Dog clamp
Welded Studs
Welded studs designed with reduced weld bases so that weld fillet does not exceed maxiumum diameter of fastener. This design is not recommended if fastener strength is important.
