document updated 17 years ago, on Jan 10, 2008
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Equipment I find useful to have
Conventions
U.S. measures thread pitch based on number of threads per inch. Metric measures pictch based on distance between threads in millimeters.
Typical sizes for the U.S.:
- Shower head — always(?) 1/2" ID NPT (0.840" thread OD) thread pitch = 14
- Garden hose thread — ALWAYS 3/4" ID (1.050" thread OD) — straight thread, washer seal, not compatible with anything else
- Indoor sink aerator — varies... 3/8", 9/16", 3/4", 13/16", 55/64", 15/16", ...
- see also: big tables of thread compatibility:
one,
two,
three,
My specific sizes
- Apartments sometimes have outside taps that require a removable handle called a "loose key" or "water key" or "sillcock key". There are at least four sizes used (1/4", 9/32", 5/16", 11/32"). My AMLI apartment requires a 5/16" key. (also, for what it's worth, that fancy-looking ring of holes is a vacuum breaker designed to prevent backflow into the residential pipes)
- My AMLI apartment bathroom sink's aerator has a pipe fitting of: ID=13/16", 27 threads per inch.
Glossary
Tables
Fractional inches
| 0.016" | 1/64"
|
| 0.031" | 1/32"
|
| 0.047" | 3/64"
|
| 0.062" | 1/16"
|
| 0.078" | 5/64"
|
| 0.094" | 3/32"
|
| 0.109" | 7/64"
|
| 0.125" | 1/8"
|
| 0.141" | 9/64"
|
| 0.156" | 5/32"
|
| 0.172" | 11/64"
|
| 0.188" | 3/16"
|
| 0.203" | 13/64"
|
| 0.219" | 7/32"
|
| 0.234" | 15/64"
|
| 0.250" | 1/4"
|
| 0.266" | 17/64"
|
| 0.281" | 9/32"
|
| 0.297" | 19/64"
|
| 0.312" | 5/16"
|
| 0.328" | 21/64"
|
| 0.344" | 11/32"
|
| 0.359" | 23/64"
|
| 0.375" | 3/8"
|
| 0.391" | 25/64"
|
| 0.406" | 13/32"
|
| 0.422" | 27/64"
|
| 0.438" | 7/16"
|
| 0.453" | 29/64"
|
| 0.469" | 15/32"
|
| 0.484" | 31/64"
|
| 0.500" | 1/2"
|
| 0.516" | 33/64"
|
| 0.531" | 17/32"
|
| 0.547" | 35/64"
|
| 0.562" | 9/16"
|
| 0.578" | 37/64"
|
| 0.594" | 19/32"
|
| 0.609" | 39/64"
|
| 0.625" | 5/8"
|
| 0.641" | 41/64"
|
| 0.656" | 21/32"
|
| 0.672" | 43/64"
|
| 0.688" | 11/16"
|
| 0.703" | 45/64"
|
| 0.719" | 23/32"
|
| 0.734" | 47/64"
|
| 0.750" | 3/4"
|
| 0.766" | 49/64"
|
| 0.781" | 25/32"
|
| 0.797" | 51/64"
|
| 0.812" | 13/16"
|
| 0.828" | 53/64"
|
| 0.844" | 27/32"
|
| 0.859" | 55/64"
|
| 0.875" | 7/8"
|
| 0.891" | 57/64"
|
| 0.906" | 29/32"
|
| 0.922" | 59/64"
|
| 0.938" | 15/16"
|
| 0.953" | 61/64"
|
| 0.969" | 31/32"
|
| 0.984" | 63/64"
|