Thin hex nuts ISO 4035 are used in bolted connections, e.g. as lock nuts to lock components and prevent accidental loosening, turning or shifting.

In addition, the nuts are also used together with indexing plungers, cam action indexing plungers, guide bushings or joint heads.

The flat design makes the hex nuts ideal for shorter threads. When mounting indexing plungers, they reduce the adjustment range only slightly, which may be of significance especially when using two lock nuts.