Weldment fixtures reduce the effect of distortion by controlling how the thermal energy from welding will affect the final assembly. As an added benefit, a fixture often provides more ergonomic and time-efficient part orientations for performing welding operations.

Fixtures are particularly useful for assemblies where small deformations will carry through to either deform or add internal stresses within the final assembly. For example, a welder would want to restrain corners and midpoints when welding a large ramp to prevent the part from curling. Without a fixture, the large heat difference across the part would cause deformation.

Welding operations are often balance the heat symmetrically across the part, limiting the amount of potential distortion. This is normally done by tack welding components together before running entire seams. As the total number of welded components increases, the difficulty, time to perform, and cost of the weld also increases.

When weldment fixtures are configured ahead of time, the welder can focus solely on the welding operation, expediting the entire process.