Which is bigger, 21mm or 13/16?

Comparing 21mm and 13/16: Which Socket Size is Larger?

In the world of socket applications, precision and correct fit are paramount. Even slight variations in socket size can significantly impact the effectiveness and safety of the connection. This is especially important when working with fasteners that require a specific socket size, such as wheel lug nuts or suspension bolts.

Often, socket sizes are expressed in metric units (millimeters) or imperial units (inches). This can lead to confusion when trying to determine which socket size is larger. To compare two socket sizes, it’s important to convert them to a common unit of measurement.

In this case, we want to compare 21mm and 13/16. To convert 21mm to inches, we divide by 25.4 (the number of millimeters in an inch):

21mm / 25.4mm/in = 0.8268in

Now, we can compare 21mm to 13/16 inch:

0.8268in vs. 0.8125in

Therefore, 21mm is larger than 13/16 inch.

This means that a 21mm socket will be slightly looser than a 13/16 inch socket when used on the same fastener. While this may seem like a minor difference, it can be enough to cause problems in some applications.

For example, if a 13/16 inch socket is used to tighten a 21mm lug nut, the lug nut may not be fully tightened and could potentially become loose. Conversely, if a 21mm socket is used to tighten a 13/16 inch bolt, the bolt may be overtightened and could potentially be damaged.

Conclusion

When it comes to socket applications, choosing the correct size is essential. If you’re not sure which socket size to use, it’s better to err on the side of caution and go with the smaller size. In our case, a 13/16 inch socket would be the better choice for a 21mm fastener.