Converting from the SAE to the metric system is a difficult and time-consuming conversion. Conversion charts are tables that allow you to transition from one unit to another while avoiding mistakes.
Many people remark that the charts in circulation are difficult to use; therefore, it is better to have one drawn up for ease of use.
You may not think you need an SAE to metric conversion calculator, yet a chart makes sit easier and can save you a considerable amount of time and effort.
To avoid costs associated with returns, placing online orders, or just working on your vehicle or around the home, you can find a mix of nuts, bolts, screws, and measurements.
Selecting the proper wrench size for basic repairs can test your knowledge. You’ll find fasteners in sizes measures in millimeters, whereas nuts and bolts can be measured in inches.
Using our guide and our metric to SAE conversion chart, you can use this to keep handy and quickly find your SAE tools sizes and how they related to a metric equivalent. (Read Socket Set Size)
By the end, you’ll have all you need to avoid the metric to SAE converter, and the answers are right at your fingertips with our SAE to metric chart.
How Do You Convert SAE to Metric?
If you have a calculator and you want to do this in your head, you can see the formula here for the conversion of SAE to Metric & Metric to SAE.
- To convert inches to millimeters, multiply inches x 25.4.
- To convert millimeters to inches, multiply millimeters x 0.039370.
Below you can find out extensive SAE to metric conversion chart that you can quickly used to determine a set of common sizes for the tools you require or the common sized fastenings you need. No matter which chart you use, you can use it for all your socket sizes, your wrench sizes, and that of your fasteners. (Read Torque Bits Sizes)
SAE to Metric Conversion Chart
| SAE | Metric | Inch |
|---|---|---|
| 5/32” | 0.156 | |
| 4mm | 0.157 | |
| 4.5mm | 0.177 | |
| 3/16” | 0.188 | |
| 5mm | 0.197 | |
| 5.5mm | 0.216 | |
| 7/32” | 0.219 | |
| 6mm | 0.236 | |
| 1/4” | 0.25 | |
| 6.5mm | 0.256 | |
| 7mm | 0.276 | |
| 9/32” | 0.281 | |
| 5/16” | 0.313 | |
| 8mm | 0.315 | |
| 11/32” | 0.344 | |
| 9mm | 0.354 | |
| 3/8” | 0.375 | |
| 10mm | 0.394 | |
| 13/32” | 0.406 | |
| 11mm | 0.433 | |
| 7/16” | 0.438 | |
| 15/32” | 0.469 | |
| 12mm | 0.472 | |
| 1/2” | 0.5 | |
| 13mm | 0.512 | |
| 17/32” | 0.531 | |
| 14mm | 0.551 | |
| 9/16” | 0.563 | |
| 15mm | 0.591 | |
| 19/32” | 0.594 | |
| 5/8” | 0.625 | |
| 16mm | 0.63 | |
| 21/32” | 0.656 | |
| 17mm | 0.669 | |
| 11/16” | 0.688 | |
| 18mm | 0.709 | |
| 23/32” | 0.719 |
Although the dimensions of the various standards may differ, items manufactured to such three standards are compatible. Hex cap screws manufactured to the dimensions specifications of any of the aforementioned standards are interchangeable with nuts manufactured to the relevant organizations’ metric specifications. The width across the flats measurements for the M10, M12, and M14 are the key differences between each of the hex cap screw standards.
Each metric standard is unique to the product. DIN 931, for example, is for metric hex cap screws with a partially threaded coarse thread. For partially threaded fine thread metric hex cap screws, DIN 960 is the specification. The ANSI B 18.2.1 specification was used to create the matching-inch series fastener.
The endeavor to fully convert metric specifications to an ISO standard is one problem with standardizing the metric system. Even though the process has begun, most industries are lukewarm to switch from DIN or metric ANSI. (Read Allen Key Sizes Chart)
Metric hex cap screws, for example, are often made to one of three standards:
- DIN 931 (DIN 933 fully threaded)
- ISO 4014 (ISO 4017 fully threaded)
- ANSI/ASME B18.2.3.1M
However, the ANSI B 18.2.1 specification encompasses eight product types under the broad heading of “Square and Hex Bolts and Screws.” Therefore, one must state the pattern of the desired product; in this Product Metric Specification
931 4014 Partially Threaded
933 4017 Fully Threaded
960 8676 Partially Threaded
While there is no precise relationship between SAE fractional and metric dimensions, many sockets are close enough that they can be used interchangeably in some situations.
What is the SAE Equivalent of 3mm?
7/64” is the same as 3mm. However, it is best to have a bit more history.
What is SAE?
The Society of Automotive Engineers (SAE) standardized the units to make them easier to use. These units were widely employed in the United States during the industrial revolution, solidifying their popularity. The industrial and construction units have adopted it as a standard industry of measurement. If you’re in the nation, you can use our conversion tables to get metric units.
What is the Metric System?
It is a measurement system devised in the 18th century. It is a measurement system in which the standard units for length, volume, and mass are the meter, liter, and gram. You quickly realize that this model of representing lengths is the most widely used around the world compared to SAE wrench sizes today.
SAE vs. METRIC UNITS
With time, SAE became widely accepted throughout the whole automobile industry. At first, the units were only utilized for vehicles, but this has since changed. At the moment, though, they are being used in all types of transportation.
When the SAE changed its name from the Society of Automobile Engineers to the Society of Automotive Engineers, planes and boats adapted the system to become the primary measurement method.
Other countries use metric units more frequently than the United States. This is the manner of operation used by major vehicle manufacturing hubs such as Japan, Germany, Korea, and France.
This has resulted in the development of SAE wrench sizes as well as metric-sized wrenches. As a result, we now have vehicles equipped with nuts and bolts in the metric system.
Because of increased production costs in the United States, the country’s major automobile manufacturers source some other countries.
As a result of this tendency, vehicles now have various components, each with its own measuring system. If the engine and its components are built in the metric system, but the rest of the vehicle is built using SAE, universal wrenches will be required, and thus your metric to inches sockets conversion using an SAE wrench size chart.
Is 10mm the same as 3/8?
ASM Metric to SAE Equivalents
| 8ths/4ths | 16ths | 32nds | 64ths | SAE Decimal | Millimeters |
|---|---|---|---|---|---|
| 1/64 | .016 | 0.397 | |||
| 1/32 | .031 | 0.794 | |||
| 3/64 | .047 | 1.191 | |||
| 1/16 | .062 | 1.588 | |||
| 5/64 | .078 | 1.984 | |||
| 3/32 | .094 | 2.381 | |||
| 7/64 | .109 | 2.778 | |||
| 1/8 | .125 | 3.175 | |||
| 9/64 | .141 | 3.572 | |||
| 5/32 | .156 | 3.969 | |||
| 11/64 | .172 | 4.366 | |||
| 3/16 | .188 | 4.763 | |||
| 13/64 | .203 | 5.159 | |||
| 7/32 | .219 | 5.556 | |||
| 15/64 | .234 | 5.953 | |||
| 1/4 | .250 | 6.350 | |||
| 17/64 | .266 | .266 | 6.747 | ||
| 9/32 | .281 | 7.144 | |||
| 19/64 | .297 | 7.541 | |||
| 5/16 | 312 | 7.938 | |||
| 21/64 | .328 | 8.334 | |||
| 11/32 | .344 | 8.731 | |||
| 23/64 | .359 | 9.128 | |||
| 3/8 | .375 | 9.525 | |||
| 25/64 | .391 | 9.922 | |||
| 13/32 | .406 | 10.319 | |||
| 27/64 | .422 | 10.716 | |||
| 7/16 | .438 | 11.113 | |||
| 29/64 | .453 | 11.509 | |||
| 15/32 | .469 | 11.906 | |||
| 31/64 | .484 | 12.303 | |||
| 1/2 | .500 | 12.700 | |||
| 33/64 | .516 | 13.097 | |||
| 17/32 | .531 | 13.494 | |||
| 35/64 | .547 | 13.891 | |||
| 9/16 | .562 | 14.288 | |||
| 37/64 | .578 | 14.684 | |||
| 19/32 | .594 | 15.081 | |||
| 39/64 | .609 | 15.478 | |||
| 5/8 | .625 | 15.875 | |||
| 41/64 | .641 | 16.272 | |||
| 21/32 | .656 | 16.669 | |||
| 43/64 | .672 | 17.066 | |||
| 11/16 | .688 | 17.463 | |||
| 45/64 | .703 | 17.859 | |||
| 23/32 | .719 | 18.256 | |||
| 47/64 | .734 | 18.653 | |||
| 3/4 | .750 | 19.050 | |||
| 49/64 | .766 | 19.447 | |||
| 25/32 | .781 | 19.844 | |||
| 51/64 | .797 | 20.241 | |||
| 13/16 | .812 | 20.638 | |||
| 53/64 | .828 | 21.034 | |||
| 27/32 | .844 | 21.431 | |||
| 55/64 | .859 | 21.828 | |||
| .875 | 22.225 | ||||
| 57/64 | .891 | 22.622 | |||
| 29/32 | .906 | 23.019 | |||
| 15/16 | .938 | 23.813 | |||
| 61/64 | .953 | 24.209 | |||
| 31/32 | .969 | 24.606 | |||
| 63/64 | .984 | 25.003 | |||
| 1.000 | 25.400 |
When you need to find fasteners and an equivalent socket, it can be tough based on the size of your job. However, since most socket sets come with both, you’ll probably find there isn’t too much aggravation besides a glance at your SAE sizes chart and finding the equivalent fasteners. (Read Standard Light Bulb Socket Size)
It is harder than it appears, and you do only have the two calculations needed to work out sizes using a calculator. But these are quickly forgotten, especially to convert millimeters to inches.
If you have the inches, and need the millimeters:
In order of increasing size…
- 1/16 inch = 2mm
- 1/8 inch = just over 3mm
- 1/4 inch = just over 6mm
- 3/8 inch = nearly 10mm
- 1/2 inch = nearly 13mm
- 5/8 inch = 16mm
- 3/4 inch = 19mm
- 7/8 inch = just over 22mm
- 1 inch = 25.4mm
For millimeters, and need the inches:
- 1mm = just over 1/32 inch
- 2mm = just over 1/16 inch
- 3mm = 1/8 inch
- 4mm = 5/32 inch (= over 1/8 inch)
- 5mm = just over 3/16 inch
- 6mm = 1/4 inch
- 7mm = 9/32 inch (= over 1/4 inch)
- 8mm = 5/16 inch
- 9mm = 3/8 inch
- 10mm = just over 3/8 inch
- 11mm = 7/16 inch
- 12mm = 15/32 inch (= 1/2 inch)
- 13mm = just over 1/2 inch
- 14mm = 9/16 inch
- 15mm = 19/32 inch
- 16mm = 5/8 inch
- 17mm = almost 11/16 inch
- 18mm = just over 11/16 inch
- 19mm = 3/4 inch
- 20mm = 25/32 inch
- 21mm = just over 13/16 inch
- 22mm = almost 7/8 inch
- 23mm = 29/32 inch
- 24mm = just over 15/16 inch
- 25mm = 1 inch
