In electrode designation E4918-X, the '490 MPa' refers to what property?

• A. Minimum yield strength
• B. Maximum tensile strength
• C. Minimum tensile strength
• D. Minimum hardness

Answer: (C)

The digits in this electrode designation convey the strength class of the weld metal, and the 490 MPa figure is the minimum tensile strength the deposited weld metal must achieve. Tensile strength is the stress a material can withstand in tension before breaking, and in welding specifications it sets the guaranteed strength of the weld rather than yield or hardness. So this value guarantees the weld metal will have at least about 490 MPa (roughly 71 ksi) of tensile strength. It isn’t about yield strength, maximum tensile strength, or hardness, which is why the correct interpretation is minimum tensile strength.