Welding Tolerances

The two dominant sources of dimensional variance in welding are placement tolerance and warpage. Tolerances are dependent on the exact nature of the parts and welds. Placement tolerance is highly dependent on the design. For example, to minimize variance on a critical assembly, mating tabs and slots should be factored into your overall design.

Less critical assemblies are hand-aligned before clamping and welding. To determine tolerance on a particular dimension on a welded assembly, you should consider any of the other dimensional tolerances for the part itself (for example, cutting or machining) which may stack with the welding tolerance.

Note 1: A welding jig can be used to help with position of mating parts during set up. A welding jig is a large brace that keeps a welding project stable in the face of pressure, heat, motion, and force. Jigs can help make welding jobs more accurate in terms of tolerances.

Note 2: Our general rule is to use jogs for all seam welds. We specify standard welding tolerances below. However, please be sure to discuss any important or critical tolerances with Protocase technical staff when specifying welding in your design.