So what is Gauge Block really? also known as Gage Blocks, created a century ago, it is a precision machined blocks of ceramic or metal (hardened alloy steel, chromium-plated steel, stainless steel, carbide) that have been crafted to an exact lengths of units of measure, made for calibrating measuring devices and used for measurement standardization in manufacturing and other industries. It is the international standard of length
In other words this tool is a machinist's best friend, why? because Calibrated Gage blocks enables you to measure equal standard measurements that everyone all over the world is using, and the fact that you would be able to trace the calibration of your Gage blocks to the international standard is what makes them so important. That is why it is critical to have a quality Gage Block in your shop, such tool must be made with quality and precision, one of those trusted companies that produces kind of product is Thread Check Inc.
More about Gage Blocks, this technology was made perfect a century ago by a Swedish Engineer, Machinist and armament inspector named Carl Edvard Johansson 1864-1943, that is why Gage Block is also called Johansson gauge or Jo block because he made a crucial improvement on Ellstrom's block that earned him a name "Master of Measurement."