SHOP REFERENCE / WRENCH RACK

Wrench Sizes in Order

Arrange combination or open-end wrenches by the size stamped on the tool. The metric and SAE charts run from smallest to largest; keep the two measurement systems separate on your rack.

Open the Socket Finder tool

MEASURE THE HEXACROSS FLATS

Match the wrench opening to the distance between opposite flat sides of a hex nut or bolt head, not the bolt’s thread diameter.

WRENCH RACK / 01

Metric mm

Common combination wrench sizes from 6 to 32 mm, in ascending order.

Metric wrench openings in ascending order
Order	Wrench size
01	6 mm
02	7 mm
03	8 mm
04	9 mm
05	10 mm
06	11 mm
07	12 mm
08	13 mm
09	14 mm
10	15 mm
11	16 mm
12	17 mm
13	18 mm
14	19 mm
15	20 mm
16	21 mm
17	22 mm
18	23 mm
19	24 mm
20	25 mm
21	26 mm
22	27 mm
23	28 mm
24	29 mm
25	30 mm
26	31 mm
27	32 mm

WRENCH RACK / 02

SAE in.

Common inch combination wrench sizes from 1/4 to 1-1/4 in., in ascending order.

SAE wrench openings in ascending order
Order	Wrench size
01	1/4 in.
02	9/32 in.
03	5/16 in.
04	11/32 in.
05	3/8 in.
06	7/16 in.
07	1/2 in.
08	9/16 in.
09	5/8 in.
10	11/16 in.
11	3/4 in.
12	13/16 in.
13	7/8 in.
14	15/16 in.
15	1 in.
16	1-1/16 in.
17	1-1/8 in.
18	1-3/16 in.
19	1-1/4 in.

AT THE BENCH

What the wrench size means

The size stamped on a fixed-size wrench describes its nominal opening across the two parallel jaws or, on a combination wrench, its matching box end. A 13 mm wrench fits a standard 13 mm hex head, while a 9/16 in. wrench fits a standard 9/16 in. hex head. The bolt’s thread size is a separate measurement: a standard M8 hex bolt commonly takes a 13 mm wrench, and a standard US 3/8 in. hex bolt takes a 9/16 in. wrench.

Check the head style

Flange, heavy hex, older DIN, and other designs may use a different head width even when the threads are the same size. Measure across flats when unsure.

Use a snug fit

Seat the wrench fully on the flats. If the open end slips or the corners are damaged, use the correct-size box end or 6-point socket when access allows.

These are practical rack orders, not a promise that every set contains every size. Extra wrenches belong between their numerical neighbors; avoid choosing a near-size SAE wrench for a metric head, or vice versa, if the fit is loose.

See standard bolt thread-to-hex-head examples → See socket sizes in order →

Size references

TEKTON’s metric combination wrench set lists 6–32 mm in 1 mm steps; its inch combination wrench set lists the 19 SAE sizes shown. Bolt Depot metric bolt head data and US bolt head data support the stated standard hex bolt examples. Check the actual fastener head before use.