hex size
also called socket size · spanner size
The distance across the flats of the shell's nut, as a length — the size of the plug socket that fits it. NGK publishes it as its own catalogue column, headed "Hex size", with the values 13.0, 14.0, 16.0, 18.0, 19.0, 20.8 and 25.4 mm across its shells; Bosch's designation table prints the same figures beside each thread (20.8 with M18 x 1.5, 16 with M14 x 1.25, 26 with the other M18, 14 and 16 with M12 x 1.25); Champion publishes `0.813 in (20.650 mm)` for the RN9YC. It does NOT follow from the thread — Bosch's own table puts hex 20.8, 16 and 14 all on M14 x 1.25 shells, so the socket cannot be derived from the joint [A13] and has to be stored. A limitation worth recording: NGK also publishes `Bi-Hex 14.0` on its KB and KG shells, a twelve-point head this numeral cannot describe as anything but 14 mm.
Hex size is a measured figure, given in millimeters or inches.
It belongs to measurement — its measurable, physical facts.
asked by the kinds that answer it
1 kind answers it, each for a single value. The same question can be reused by unrelated kinds — one meaning, many homes.
asked by kinds that answer it
The same question can be reused by unrelated kinds — one meaning, many homes.
| kind | how many |
|---|---|
| spark plug | one |