Table. Minimum fillet weld sizes
For non low-hydrogen processes without preheat calculated in conformance with 4.8.4, T equals thickness of thicker part joined; single pass welds shall be used. For non low-hydrogen processes using procedures established to prevent cracking in conformance with 4.8.4 and for low-hydrogen processes, T equals thickness of thinner part joined; single pass requirement shall not apply.
1. Except that the weld size need not exceed the thickness of the thinner part joined.
2. Minimum size for cyclically loaded structure shall be 3/16in [5mm].