Nuts - American Sizes

Nuts in imperial dimensions / with inch threads

Only nuts in with inch threads fit the respective inch thread bolt . As with the bolts, the outer diameter of the thread and the pitch are specified in threads per inch. An example: a nut with the designation 3/8"-24 fits on a bolt thread with a diameter of 3/8" (= 9.5 mm) and a thread pitch of 24 threads to 25.4 mm (for the mathematicians among us: 1.08 mm). With a nut, of course, you can only measure the "hole", not the outer diameter of the thread. The technician does not refer to "hole", but core diameter. But each core diameter corresponds to a specific thread. With this background and the table, you can then draw fairly reliable conclusions about the thread. The suspicious mechanic then measures the thread pitch with a gauge. Our Tech Tips contain lists of the thread diameters that match the cores.

Is the hexagon also imperial?

The external hexagon of common nuts and castellated nuts and the internal hexagon or 12-point nuts, which most people simply refer to as "Allen nuts", also correspond to the inch measurement system, i.e. they are specified in fractions. At W&W Cycles the "Allen nuts" are called hexagon and hexagon socket nuts because the word Allen is a registered trademark. That´s why you have to use such terms in a web store. By the way: certain hexagon sizes also correspond to certain threads. We specify the appropriate wrench sizes for the bolts.