Faucet Thread Measurements
16 mm
16mm = 0.630"
Thread diameter
0.6194"
15.731 mm
5/8"
5/8" = 0.625"
5/8" = 15.875 mm
Thread diameter
0.6205"
15.761 mm
16.5 mm
16.5mm = 0.650"
Thread diameter
0.6446"
16.372 mm
This size is sometimes referred to as "Tom Thumb". I prefer "16.5mm" myself.
11/16"
11/16" = 0.6875"
11/16" = 17.4625 mm
Thread diameter
0.6842"
17.377 mm
18 mm
18mm = 0.7087"
Thread diameter
0.6932"
17.607 mm
0.7043"
17.888 mm
18.5 mm
18.5mm = 0.7283"
Thread diameter
0.7256"
18.429 mm
This size is sometimes referred to as "Tiny Junior". I prefer "18.5mm" myself.
3/4"
3/4" = 0.75"
3/4" = 19.05 mm
Thread diameter
0.746"
18.951 mm
0.7488"
19.020 mm
20 mm
20mm = 0.7874"
Thread diameter
0.774"
19.667 mm
13/16"
13/16" = 0.8125"
13/16" = 20.6375 mm
Thread diameter
0.804"
20.418 mm
21.5 mm
21.5mm = 0.8465"
Thread diameter
0.8336"
21.172 mm
This size is sometimes referred to as "Junior". I prefer "21.5mm" myself.
0.8342"
21.189 mm
21.5 mm Moen
21.5mm = 0.8465"
Thread diameter
0.8426"
21.402 mm
55/64"
55/64" = 0.8594"
55/64" = 21.828 mm
Functionally identical to 22mm
Thread diameter
0.855"
21.704 mm
22 mm
22mm = 0.8661"
Functionally identical to 55/64"
Thread diameter
0.857"
21.742 mm
15/16"
15/16" = 0.9375"
15/16" = 23.8125 mm
Thread diameter
0.923"
23.448 mm
24 mm
24mm = 0.9449"
Thread diameter
0.936"
23.783 mm
0.9551"
24.258 mm
28 mm
28mm = 1.1024"
Thread diameter
1.089"
27.670 mm
Dial Caliper Photos of Measurements
16 mm
16mm = 0.630 inches
16mm thread diameter
0.619 inches
16mm thread diameter
15.731 mm
5/8"
5/8" = 0.625 inches
5/8" = 15.875 mm
5/8" thread diameter
0.621 inches
5/8" thread diameter
15.761 mm
16.5 mm
16.5mm = 0.6496 inches
16.5mm thread diameter
0.6446 inches
16.5mm thread diameter
16.372 mm
11/16"
11/16" = 0.6875 inches
11/16" = 17.4625 mm
11/16" thread diameter
0.684 inches
11/16" thread diameter
17.377 mm
18 mm
18mm = 0.7087 inches
18mm thread diameter
0.693 inches
18mm thread diameter
17.607 mm
18.5 mm
18.5mm = 0.7283 inches
18.5mm thread diameter
0.7256 inches
18.5mm thread diameter
18.429 mm
3/4"
3/4" = 0.75 inches
3/4" = 19.05 mm
3/4" thread diameter
0.746 inches
3/4" thread diameter
18.951 mm
20 mm
20mm = 0.7874 inches
20mm thread diameter
0.774 inches
20mm thread diameter
19.667 mm
13/16"
13/16" = 0.8125 inches
13/16" = 20.6375 mm
13/16" thread diameter
0.804 inches
13/16" thread diameter
20.418 mm
21.5 mm
21.5mm = 0.8465 inches
21.5mm thread diameter
0.8336 inches
21.5mm Moen thread diameter
21.172 mm
21.5 mm Moen
21.5mm = 0.8465 inches
21.5mm Moen thread diameter
0.843 inches
21.5mm Moen thread diameter
21.402 mm
55/64"
55/64" = 0.8594 inches
55/64" = 21.828 mm
Functional identical to 22mm
55/64" thread diameter
0.855 inches
55/64" thread diameter
21.704 mm
22 mm
22mm = 0.8661 inches
Functional identical to 55/64"
22mm thread diameter
0.857 inches
22mm thread diameter
21.742 mm
15/16"
15/16" = 0.9375 inches
15/16" = 23.8125 mm
15/16" thread diameter
0.923 inches
15/16" thread diameter
23.448 mm
24 mm
28mm = 0.9449 inches
24mm thread diameter
0.936 inches
24mm thread diameter
23.783 mm
28 mm
28mm = 1.1023 inches
28mm thread diameter
1.089 inches
28mm thread diameter
27.67 mm
Hidden Aerator Keys - A different use...
Which thread sizes fit inside which keys?
We can use these keys in a different way: by comparing faucet aerator threads to the inside measurement of these keys!
9/16"
Fits in the yellow key
5/8"
Fits in the green key but not the yellow key
11/16"
Fits in the red key but not the green key
3/4"
Fits in the grey key but not the red key
13/16"
Almost fits in the grey key
15/16"
Too large to fit in any key
16 and 16.5mm
Fits in the green key but not the yellow key
18 and 18.5mm
Fits in the red key, barely, but not the green key
20mm and larger
Too large to fit in any key