A positive locking device is a device used in conjunction with a fastener in order to positively lock the

fastener A fastener (US English) or fastening (UK English) is a hardware device that mechanically joins or affixes two or more objects together. In general, fasteners are used to create non-permanent joints; that is, joints that can be removed or disman ...

. This means that the fastener cannot work loose from

vibration Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point. The word comes from Latin ''vibrationem'' ("shaking, brandishing"). The oscillations may be periodic function, periodic, such as the motion of a pendulum ...

s. The following is a list of positive locking devices: *A

split beam nut A split beam nut, also known as a split hex nut. or slotted beam nut, is a locknut with slots cut in the top that separate the outside end into two. or more sections that are bent slightly inward, making the thread diameter undersized in the slotted ...

castellated nut A castellated nut, sometimes referred to as a castle nut, is a nut with slots (notches) cut into one end. The name comes from the nut’s resemblance to the crenellated parapet of a medieval castle. Castellated nuts are sometimes referred to inc ...

and a

split pin A split pin, also known in the United States of America as a cotter pin or cotter key, is a metal fastener with two tines that are bent during installation, similar to a staple or rivet. Typically made of thick wire with a half-circular cross s ...

*A hex nut or

cap screw A screw and a Bolt (fastener), bolt (see ''#Differentiation between bolt and screw, Differentiation between bolt and screw'' below) are similar types of fastener typically made of metal and characterized by a helix, helical ridge, called a ''m ...

and a tab washer *A hex nut or cap screw and a lock plate * Safety wiring with various types of fasteners File:Nut lock plate.svg, A locking plate File:Nut tab washer.svg, A tab washer

References

*{{cite book , url=http://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentid/99861 , title=AC 43.13-1B - Acceptable Methods, Techniques, and Practices - Aircraft Inspection and Repair , chapter=7. Aircraft Hardware, Control Cables, and Turnbuckles , chapter-url=http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/list/AC%2043.13-1B/$FILE/Chapter%2007.pdf , date=8 September 1998 , access-date=2012-12-11 , ref={{sfnref, AC43.13, 1998 Fasteners