Locking Fasteners

Locking fasteners come in many varieties and styles to help keep your fastener assemblies secure and resist loosen from vibration. Locking nuts and washers are great tools to keep assemblies from accidental loosening, basically they stop things from falling apart! But what kind of locking nut or washer should you buy? Below we explain some of the popular types to help you choose.

Lock Washers

Lock washers are washers with designed changes to add extra friction or tension to your fastener assembly to prevent loosening. Each lock washer is engineered to work for different applications, if you are unsure if the hardware you are selecting is appropriate, make sure to consult an engineer.

Click the name of any type of lock washer or nut you would like to know more about or buy directly from our website.

Lock Washer Type	Description	Image
External Tooth “External Star”	External tooth lock washers are serrated and create tension between the teeth and the installation surface. This increased tension can make it harder for a fastener assembly to vibrate loose.
Internal Tooth “Internal Star”	Internal tooth lock washers have bent teeth that are designed to create tension and friction on the inside of a bolt head or against the nut. They are often chosen over external tooth lock washers due to their cleaner finish.
High Collar Split Ring	High collar lock washers are similar to regular split ring washers except they are made to fit under the head of a socket cap screw. They have a smaller outer diameter designed to fit into a counter-bored hole.
Split Ring	Split ring lock washers are washers with a cut in them and bent into a helicoil shape. As the nut loosens, extra pressure is applied from the expanding lock washer which can stop a bolt from loosening unintentionally

Lock Nuts

Lock nuts are nuts that have been altered in some way to deter them from vibrating loose. Below are a few of the more common types of lock nuts you are likely to come across.

Lock Nut Type	Description	Image
Castle	Castle nuts, while not technically lock nuts, can function as lock nuts after installation. They require that a cotter pin be placed through a hole in a bolt and through the crown of the nut. We consider these to be lock nuts because the cotter pin will hold the nut in place if it comes loose.
Flange Serrated	Flange serrated nuts have one wide side that acts as an integrated washer. The washer side has serrations which, when tightened, can help prevent loosening by adding extra friction to the assembly.
Keps-K	Keps K lock nuts Have an attached spinning washer with teeth that can dig into the assembly. They are similar to that of an external tooth lock washer combined with a nut.
Nylon Insert	Nylon insert lock nuts are a taller nut with the same nylon insert. Threads cut into the insert as installed resulting in a better grip to help prevent a fastener assembly vibrate loose.
Nylon Jam “Thin”	Nylon Jam lock nuts are a low profile nut that have an internal nylon insert. As the bolt is screwed on the threads cut into the nylon holding them in place and preventing vibrations from loosening them.
“Stover” Cone Prevailing Torque	Stover lock nuts have chamfered corners. The distortion in the top threads from the shape of the bolt create resistance to loosening. This is a better choice for high heat applications because no nylon insert is used.
Two Way Reversible	Two way reversible lock nuts have indents on the outside flats of the nut causing distortions of the internal threading. These distortions create resistance of the mating part.

NOTE: We also offer thread locker solutions that can provide a low, medium or high level grip to prevent assemblies from loosening as well.