In the AWS designation ER70T-6, what does the digit '0' indicate?

In the AWS designation ER70T-6, the digit '0' is indicative of the filler metal being suitable for a flat and horizontal position of weld. This designation is part of the American Welding Society's classification system, where the numbers that follow the letter indicate various properties and intended applications. In this case, the '0' specifies that the filler metal is designed for use in welding positions that are predominantly flat and horizontal, which are some of the most common and stable positions used in welding.

This interpretation helps welders choose the appropriate filler metal depending on the positions they will be welding in, ensuring better control and quality of the welds, especially in applications requiring higher precision or strength. Understanding such details in designations allows for better selection of materials to match specific job requirements.

Other designations like the '6' in ER70T-6 refer to properties like tensile strength and adjustments for specific environments, which further enhance the suitability of the filler metal for varied applications. However, it's important to note that the number '0' relates specifically to the welding positions appropriate for the filler material.