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

AdvantagesApplicationsVendors 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 o Increase contact friction

o Increase interference fitCompressionModified threads

• Chemicalo Anaerobic

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

www.parker.com/stratoflex/products/locking.asp

www.boltscience.com/pages/vibloose.htm

www.longlok.com

www.jlanfranco.com/jl_products.php