Engineering departments in the United States employ US-standard units and produce in the United States with **inch-sized steel** and other inch-sized components. Metric is used in our UK engineering, and we produce in the UK utilizing metric components. Engineering departments in Europe use **metric units** and produce in Europe with millimeter-sized components.

In terms of actual measurements, an engineer might measure length with a micrometer, measure diameter with a caliper, and so on. But these are technical processes that lie behind the work of an engineer. The general practice is for engineers to use metric measurements whenever possible because they are more accurate and provide information about size that can't be obtained otherwise. For example, an engineer might measure the clearance between two parts of an engine by using a micrometer to determine how much material there is between them, rather than estimating it from geometric considerations only capable of producing an approximate value.

When you look inside a car engine, you will usually find metal parts with metric sizes. For example, a piston has a height of 100 mm, while a cylinder has a diameter of 90 mm. Even if you didn't know this, you could still guess that the distance between the top of one piston and the bottom of **the next one** is about 90 mm, since that's the same as the diameter of the cylinder.

The United States, on the other hand, employs **the US Customary System** of Measures—also known as English Units—to define weights and measurements. Because the metric system is decimal, it is easier to understand than the non-decimal US system. The conversion factor from ounces to grams is 8 oz. = 1 lb.

Decimal numbers are also easier to calculate with. For example, there are 10 times more seconds in a day than minutes or hours. This becomes important when trying to work out how long a person has been dead for because 100 percent of someone's life equals one whole day. There are 1000 minutes in a day and 60 seconds in a minute so 100 percent means that we need to divide 1000 by 60 to find out how long they had been dead before they were found. In **this case**, it was nearly two months!

Oddly enough, the metric system was originally designed as a replacement for the outdated imperial system. The French Academy of Sciences created the metric system in 1790 after learning about the new American measuring tools at the Paris Exhibition.

Today, almost all countries use **some form** of the metric system for measurement. Only Iran, Iraq, Pakistan, Syria, and Yemen still use the old imperial system instead.

Which system is better? That depends on which features you like best.

Because most fasteners, machine components, pumps, pipelines, and construction supplies are offered in imperial or US customary units, many mechanical and civil engineers in Canada choose to work with imperial units. The overall size of new buildings are normally measured in SI units. However, building permits must be filed in inches or millimeters, depending on the zone in which the building is located.

In addition, the Canadian government uses the metric system for some measurements related to food safety and chemical manufacturing but retains **the imperial system** for most other purposes. For example, gasoline prices are listed in gallons rather than Lbs or kg.

Finally, although the metric system is used mostly in Europe, North America prefers the imperial system. Many countries have adopted both systems, so there are no real advantages or disadvantages to using one system over the other.

The main reason why Canada hasn't yet made the switch to metric is due to cost. Some industries may require **special tools** to work in metric, while others may not be able to be sold in metric sizes. For example, a metal fabricator who needs to buy bolts with metric-size heads can't simply purchase them from **a hardware store** that sells **only inches-based products**. There are also legal requirements to retain the imperial system for some applications such as road signs until 2019.

Measurement units Whereas most nations use **the metric system**, which includes measurement units such as meters and grams, the imperial system is utilized in **the United States**, where objects are measured in feet, inches, and pounds. Although the two systems can be used interchangeably, it's best not to mix them because conversions will need to be made to convert from **one system** to the other.

Conversions Between the Two Systems: To convert from the metric system to the imperial system, multiply the number by 16.35. For example, to convert 1 meter into inches, multiply by 16.35; to convert 2,000 grams into ounces, multiply by 16.35. To convert from the imperial system to the metric system, divide by 0.0353. For example, to convert 20 inches into centimeters, divide by 0.0353; to convert 4.5 pounds into grams, multiply by 0.0353.

It is important to note that although these conversions are easy to perform with basic math, there are different ways of measuring some quantities in each system that may not be apparent until after you've completed a conversion. For example, when converting distance measurements, it's important to remember that the metric system is based on 10,000 millimeters, or 0.01 kilometers, while the imperial system is based on 12 inches, or 30.5 centimeters.