Related Resources: weld

Minimum Fillet Weld Size per AWS D1.1 Table

Welding Engineering and Design

Minimum Fillet Weld Size per AWS D1.1 Table.

When weld fillet size is not specified on engineering drawing, the following general guidance apply per. AWS D1.1. Weld sizes should be determined based on structural requiremnts and specified.

International standards do not generally provide requirements or guidance on minimum fillet weld sizes.

Table. Minimum fillet weld sizes

Base metal thickness (T) a		Minimum size of fillet weld b
in	mm	in	mm
T < 1/4	T < 6	1/8 c	3 c
1/4 < T < 1/2	6 < T < 12	3/16	5
1/2 < T < 3/4	12 < T < 20	1/4	6
¾ < T	20 < T	5/16	8

Where:

T = Base materials Thickness

Notes

a. 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.

b. Except that the weld size need not exceed the thickness of the thinner part joined.

c. Minimum size for cyclically loaded structure shall be 3/16in [5mm].