December 03, 2001 Burke Jardine Michael Johnson Matthew Dalebout Self-Locking Threaded Fasteners

Objective To understand how self-locking fasteners work, what they are used for and where to find them.

Self-Locking Threaded Fasteners Outline  Conventional Nut vs Self-Locking Threaded Fasteners Comparison  Advantages  Applications  Vendors and Where to Find Them

Standard Nut vs Self Locking Threaded Fastener Comparison:  Standard Nuts  Self Locking Threaded Fasteners

Standard Nuts  Standard Nuts: Relies on friction between the nut surfaces.

Problems with Standard Nuts  Vibration  Thermal Effects  Fatigue  Stress Distribution  Strain Deformation  Insufficient Tightening Torque  Frequent Servicing/High Use Accidental Disassembly Due to :

What are self-locking fasteners? Self Locking Threaded Fasteners Prevent Accidental Disassembly by: Preventing Fatigue Resisting Vibration Reducing Stress Concentration

Vibration After Pre-Load

Types of Self-Locking Fasteners Mechanical oIncrease contact friction oIncrease interference fit Compression Modified threads Chemical oAnaerobic

Why do self-locking work? Example : Stress Distribution

Where Are They Found and Who Sells Them? ANY HARDWARE STORE Stores selling over the WWW

Additional Information ing.asp