SHOP REFERENCE / SOCKET RAIL
Socket Sizes in Order
Arrange your metric and SAE sockets from smallest to largest. These charts show the opening sizes marked on sockets; your set may skip some sizes or include others.
Open the Socket Finder toolKeep metric and SAE sockets on separate rails. Match the socket to the fastener head, then check that it seats fully.
Metric mm
Read down the table, smallest to largest.
| Order | Socket size |
|---|---|
| 01 | 4 mm |
| 02 | 4.5 mm |
| 03 | 5 mm |
| 04 | 5.5 mm |
| 05 | 6 mm |
| 06 | 7 mm |
| 07 | 8 mm |
| 08 | 9 mm |
| 09 | 10 mm |
| 10 | 11 mm |
| 11 | 12 mm |
| 12 | 13 mm |
| 13 | 14 mm |
| 14 | 15 mm |
| 15 | 16 mm |
| 16 | 17 mm |
| 17 | 18 mm |
| 18 | 19 mm |
| 19 | 20 mm |
| 20 | 21 mm |
| 21 | 22 mm |
| 22 | 23 mm |
| 23 | 24 mm |
| 24 | 25 mm |
| 25 | 26 mm |
| 26 | 27 mm |
| 27 | 28 mm |
| 28 | 29 mm |
| 29 | 30 mm |
| 30 | 31 mm |
| 31 | 32 mm |
SAE in.
Read down the table, smallest to largest.
| Order | Socket size |
|---|---|
| 01 | 5/32 in. |
| 02 | 3/16 in. |
| 03 | 7/32 in. |
| 04 | 1/4 in. |
| 05 | 9/32 in. |
| 06 | 5/16 in. |
| 07 | 11/32 in. |
| 08 | 3/8 in. |
| 09 | 7/16 in. |
| 10 | 1/2 in. |
| 11 | 9/16 in. |
| 12 | 5/8 in. |
| 13 | 11/16 in. |
| 14 | 3/4 in. |
| 15 | 13/16 in. |
| 16 | 7/8 in. |
| 17 | 15/16 in. |
| 18 | 1 in. |
| 19 | 1-1/16 in. |
| 20 | 1-1/8 in. |
| 21 | 1-3/16 in. |
| 22 | 1-1/4 in. |
| 23 | 1-5/16 in. |
| 24 | 1-3/8 in. |
| 25 | 1-7/16 in. |
| 26 | 1-1/2 in. |
WORKBENCH NOTES
How socket sizing works
The size stamped on a standard hex socket describes its opening across opposite flats. For example, a 19 mm socket fits a hex head measuring about 19 mm across flats; a 3/4 in. socket is marked by its nominal inch opening. That size is different from the bolt’s thread diameter.
The drive size—such as 1/4, 3/8 or 1/2 in.—describes the square connection to your ratchet. It does not describe the opening around the fastener. Sets differ by drive size, depth, and 6-point or 12-point shape, so no single kit contains every size shown here. Use a socket that fits snugly; do not force a loose one.
This is a practical organization guide, not a claim that every size appears in every socket set. Larger specialty sockets are available beyond these charts.
Metric socket size chart and 6-point vs 12-point guide → SAE socket size chart and 6-point vs 12-point guide → Put metric and SAE wrenches in order → Choose a 1/4, 3/8 or 1/2 in. socket drive → See the metric to SAE conversion chart → Need the closest metric or SAE size? Use Socket Finder →Size references
The order and availability ranges were checked against manufacturer socket-set size lists: