Choosing between metric or imperial sizing is a decision you might have to make if you’re in the market for fasteners. Quite simply, imperial fasteners are measured using imperial units of measurement, and metric fasteners are measured using metric units. The debate over which measurement system to use has been going on for over a century, but even though metric is now the preferred system worldwide, ultimately it comes down to personal preference.
Before you make your choice, it’s important to understand how each system works and then compare the pros and cons. Imperial measurements originated from an old English system based on measurements from a variety of cultures. The system was continually refined, but it was never standardized, so an inch in the United States might not be the same length as an inch in Australia, for example. This variation makes it very difficult to collaborate with other countries and is one of the main drawbacks of the imperial system.
The metric system, created in France, uses a standardized set of base units that are internationally accepted. The measurements follow a logical progression of millimetres built on factors of ten, making it simple to subdivide if necessary. In contrast, the fractional nature of imperial measurements is challenging to understand, making it just as tricky to order the correct fasteners. For example, if you wanted half of a 16/32 bolt, you would need to order a 16/64 bolt! So, unless you’re well-versed in imperial fractions, it would be wiser to go with a metric measurement, where you simply need to know that ten-millimetres equals a centimetre, or that a 10-millimetre bolt is twice the size of a 5-millimetre bolt.
Another consideration is that only select areas in the United States still use the imperial system and even there, most major industries are switching to metric. It may seem like a trivial issue on the surface but choosing metric over imperial measurements will have a far more positive influence on how you operate your business and in turn, your level of customer service. When a customer orders metric fasteners, they can be confident that the size they ordered is the size they’re going to get. A system that is this simple and so widely recognized, must be the obvious choice.