Knowing what wrench size to use when removing or installing bolts on your vehicle or any piece of equipment saves you a lot of time as you work. Sometimes, bolt manufacturers give you a clue about the correct wrench size to use with their bolts right on the package. Many times, however, you do not have this information handy. Either way, you have some practical methods at your disposal to determine the wrench size for a given bolt. This will save you time when making repairs on your car or any piece of equipment.

Finding a Wrench for Standard-and Metric-Sized Bolts

Step 1

Read the size number given on the bolts’ package, if you just purchased them. For example, it may read: 1/2 – 10 UNC – 2A x 1 3/4. A package containing metric-sized bolts will have an “M” before the first number.