What is the margin of error or accuracy of Westcott stainless steel rulers?

Westcott stainless steel rulers are marketed as home-and-office products.  When they are used in a manufacturing setting in place of rulers that are specifically manufactured and marketed as being "scientific rulers" (costing much more), it is up to the customer to perform a reliability study from a sampling of our rulers and decide if they will meet their compliance needs.  Requirements do vary by Industry, which is why we direct the customer to decide on the suitability of our rulers on their own.

Please see the letter attached for further information.