Also known as machinists’ rules, these rulers ensure reliable, repeatable measurements. They meet Fed. Spec. GGG-R-791H, which establishes uniform standards for ruler accuracy, graduations, and size. All have a corrosion-resistant satin-chrome finish that reduces glare and wear-resistant etched markings. Inch and inch/metric rulers are labeled with numeric increments that are less than 1" for quick reading.