RS PRO Steel Lock Nut, 4-40 (NM)in

Introducing the range of RS PRO Lock Nuts, a high-quality fastener locking solution for connecting and tightening a bolt or screw in a wide range of applications to prevent it from loosening and locking it into place. Each fastener is made from steel with a zinc coating, making them much more cost-effective than their stainless-steel counterparts, while still offering a high level of protection against surface rust and oxidisation.

Hex nuts are designed specifically for ease of use and simplicity. They are used for applications where the fastener needs to be tightened or loosened, most commonly when something needs additional security alongside the bolt to ensure a secure fixing. The main benefit of hex nuts is that they are easy to install and are available in a range of sizes to suit the application needs. Hex nuts are most commonly used in:

• Household and DIY applications


• Building and construction


• Automotive, marine and aerospace

RS PRO is our own brand range and brings you a wide range of high-quality, great value products offering you more choice. Trusted by engineers all over the world, every part of every RS PRO product has been rigorously tested against demanding industry standards - they’re only given the RS PRO seal of approval if we’re confident of their exceptional quality, which means you can be confident too.