In a combined assembly of groove and fillet welds, which should be welded first?

Welding a combined assembly of groove and fillet welds should begin with the groove welds for several reasons related to both structural integrity and practical considerations.

First, groove welds typically have a larger cross-sectional area and are designed to carry significant loads, acting as the primary means of load transfer in many structural applications. By completing the groove welds first, you can ensure that the main structural integrity is established before adding the fillet welds, which generally serve to provide additional strength and reinforcement.

Moreover, welding the groove welds first allows for proper heat management. Groove welds often involve deeper penetration, which results in more significant thermal effects. If fillet welds were completed first, the heat from welding the groove weld could potentially distort the fillet welds, compromising their performance and the overall assembly.

Additionally, finishing the groove welds first helps in better accessibility for the welder, allowing them to work more comfortably and effectively when executing the fillet welds afterward without obstruction from previously completed work.

This sequence is consistent with good welding practices aimed at maintaining the quality and performance of the welds throughout the construction process.