Some questions may test the depth of the welder’s understanding of the hazards associated with welding and will go beyond obvious safety rules.

It is common for welders to be responsible for correctly setting up their equipment. This includes knowing what equipment and consumables are needed for each welding process. Welders need at least 80% Argon in the shielding gas mixture or spray transfer will not be achievable.

Welders may be responsible for making decisions about the choice of suitable materials for a given application. Understanding the technical information, such as electrode classifications, related to equipment and consumables is important.

Welders need to be able to identify, understand, and remedy welding discontinuities.

For welding and many other jobs in manufacturing and construction, it is essential that employees be able to read a ruler to accurately interpret measurements.

Many companies use the metric system of measurement. Welders need to be able to use this system of measurement as well as US standard units. 

Welders may be required to use more specialized measurement equipment. Calipers are used for material identification, layout, and inspection. Calipers measure thickness, inside diameters, outside diameters and depth. 

The interpretation of weld placement is essential for welders to accurately assemble their work. Arrow side or other side is a common mistake in interpreting prints. This can be a costly mistake when welds are inaccurately placed and rework is needed to fix the incorrect placement. 

The necessity for correct weld placement is reinforced when the weld is specified to be intermittent. Weld length and pitch are specified to meet design and engineering requirements, and it is important that the welder be able to interpret and recognize the importance of this information. 

Weld size is specified for reasons similar to the reasons why weld location and length is specified in a print. Compromising any of these features may put the welded project at risk for failure under the stresses it needs to endure.

Where weld size is specified, a weld fillet gauge may be used to check that the weld size is correct. Therefore, welders must know how to use weld fillet gauges to accurately measure the size of a weld. 

During fabrication and assembly, welders are often required to check for squareness and accuracy. This can often require the addition or subtraction of fractions to determine the amount of variance. 

Welders need to be able to check measurements with their prints and use the information provided to check the accuracy of their work.