What characteristic of locknuts helps prevent loosening?

Locknuts are specifically designed to prevent loosening due to vibrations and movement in a mechanical assembly. The characteristic that helps in this regard is that they are locked against each other. When two locknuts are used together, the tightening of the first nut creates pressure on the second nut, which effectively locks them in place. This reaction helps maintain a secure connection and minimizes the risk of loosening caused by dynamic loads or vibrations.

The other characteristics, such as being lightweight or made of stainless steel, do not contribute directly to preventing loosening. While these may be beneficial in terms of application and resistance to corrosion, they do not address the fundamental purpose of securing the connection as the locking mechanism between the nuts does. Additionally, the various colors do not have any practical impact on their functional ability to resist loosening; they are typically more about aesthetics or identification. Therefore, the locking feature is the primary reason locknuts are effective in keeping components securely fastened.