Protocase Resources

The information below is intended to be helpful for customers who wish to learn more about enclosure design. Also, please use our online support if you have questions for our expert design staff.


Fabrication Tolerances for Dimensional Variance in Stainless Steel Bar Stock and Machined Parts

Standard Tolerances For Stainless Steel Bar Stock

Usually, choosing material thickness is one of the first steps a designer takes when starting a project. We work with nominal thicknesses, so it's important to know the thickness tolerance on the material you chose, in order to know if the final product will be suitable for your application. It's also important when working with bar stock that you factor in finish tolerances. For example, if you add a finish such as powdercoat, you add more thickness - this should be factored into your design at the beginning.

Stocked Stainless Steel ( Rectangular Bar Stock )

Size Alloy ASTM Standard Thickness Tolerance
(1" x 1" | 25.4mm x 25.4mm) 304 ± 0.009"
(1" x 2" | 25.4mm x 50.8mm) 304 ± 0.015"
(2" x 2" | 50.8mm x 50.8mm) 304 ± 0.016"
(3" X 3" |76.2mm x 76.2mm) 304 ± 0.047"

Stocked Stainless Steel alloy ( Round Bar Stock)

Specified Thickness Alloy Tolerance
1" | 25.4mm TP304 ± 0.025" | 0.06mm
2" | 50.8mm TP304 ± 0.003" | 0.08mm