jam nut

noun

1. lock nut ( def 2 ).

Word History and Origins

Origin of jam nut¹

First recorded in 1860–65

Example Sentences

After having the desired pressure, screw the jam nut down tight on the pressure screw.

From Project Gutenberg

There are two little brass nuts on the top of the stem of the governor, one a thumb nut and the other a loose jam nut.

From Project Gutenberg

To increase the speed, loosen the jam nut and then turn the thumb nut back slowly, watching the motion of the engine all the time.

From Project Gutenberg

The second nut is technically known as a “jam nut,” or “lock nut.”

From Project Gutenberg

To set it, unscrew the jam nut and apply the key to the pressure screw.

From Project Gutenberg