Slotted hex nuts and castle nuts have six sides and a hollow center with internal threading allowing it to fit over an externally threaded shaft; offering very similar dimensions as standard finished hex nuts. The ‘slotted’ reference is easily identifiable by the grooves cut into the top of the nut. Slotted hex nuts are commonly used with an externally threaded fastener or bolt that has a hole drilled through it at a specific point. The slotted hex nut will thread over the bolt, and a cotter pin will be inserted through the hole to lock the nut to the bolt. The cotter pin will fit comfortably between the slots of the nut to ensure the connection is secure. Castle nuts offer a similar design with slots in the top as well; however, they are designed for use with cotter pins and wire. A castle nut offers stronger security for use in high stress applications that a slotted hex nut might not be sufficient. Both slotted hex and castle nuts are ideal for many applications that require extra security or those with vibrations that can cause a traditional nut to loosen. They can be found in machinery, automotive, and construction industries. When choosing the best option, be sure to take any environmental conditions into consideration for plating or material selections.
If your project requires a bolt drilled per print, please reach out as Fasteners Etc. can assist you with manufacturing needs as well. Assembly options are available too, reach out for a custom quote on your full project.
