Final answer:
The term 'center-to-center spacing' refers to the distance between the centers of two intermittent fillet welds in welding.
Step-by-step explanation:
In the context of welding, the term center-to-center spacing refers to the distance between the centers of two intermittent fillet welds. It is also known as pitch or gap. This spacing is important because it determines the strength and integrity of the weld joint. A smaller spacing increases the number of welds, providing more strength to the joint. Conversely, a larger spacing reduces the number of welds, potentially compromising the joint's strength.