What are Dzus Fasteners?

 

Self Ejecting Dzus FastenerDzus Fasteners, Quarter Turn or Turnlock Fasteners as they are also known, allow the quick removal of body panels, doors and other panels that need to be removed frequently. Dzus Fasteners use a cam style design to secure the fasteners. The fasteners have a notch machined into the shaft which locks onto a spring. The constant torque of the spring ensures the Dzus Fasteners remain fastened. Removal and installation of the fasteners only requires a quarter or 90 degree turn, compared to a standard bolt and nut which require multiple turns.

The most common sizes of Dzus Fasteners are 5/16″ and 7/16″, which refers to the shaft diameter of the button. Various lengths of buttons are available, this is known as the Grip Length. Visit our Measuring Dzus Fasteners page for a guide to measuring them correctly.

 

Types of Dzus Fasteners

There are many styles of Dzus Fasteners available, which are all available in the Bullant Performance Products Store.


» Oval Head

Oval Head Dzus FastenerOval Head Dzus Fasteners are the most common style of Dzus Fasteners used and feature a straight slot which can be fastened with a standard screwdriver or dzus tool. The standard head diameter is 11/16” (17.2mm) however “Big Head” fasteners are also available which have a 1” (25.4mm) head. Big Head fasteners are especially good for use on fibreglass panels which are prone to wear. Oval Head Dzus Fasteners are available in steel and aluminium.


» Undercut

Undercut Dzus FastenersUndercut Dzus Fasteners allow the fastener to stay with the panel. This is accomplished by a slot that is machined under the head of the fastener. The button is placed through the panel, a nylon washer is then fitted to the button. Undercut Dzus Fasteners are available in steel and aluminium.


» Allen Head

Allen Head Dzus FastenerAllen Head Dzus Fasteners feature an Allen or Socket head for use with a 3/16” Allen Key. The advantage of using this style of fastener is that the socket is less prone to wear than straight slot fasteners. Many customers prefer using an Allen Key to a screwdriver as there is less risk of accidental paint damage. A downside to this style is that if in an emergency a panel has to be removed screwdrivers are usually more readily available than Allen Keys. Allen Head Dzus Fasteners are available in steel and aluminium.


» Flush Head

Flush Head Dzus FastenersFlush Head Dzus Fasteners or Countersunk Fasteners sit flush with the panel surface. These are usually used on aluminium and steel panels which can be dimpled using a Dimple Tool to accept the fastener. These fasteners provide a more aerodynamic finish and are often used in drag racing. Flush Head Dzus Fasteners are available in steel and aluminium with a straight slot or Allen Head.


» Winged

Winged Dzus FastenersWinged Dzus Fasteners or Butterfly Fasteners do not require any tools to fasten or remove them. The fasteners have a built-in handle on top of the fastener which is used to turn the button. These are available as oval head and self-ejecting fasteners.


» Self-Ejecting

Self Ejecting Dzus FastenerSelf-Ejecting Dzus Fasteners comprise a spring loaded fastener which is captured within the body of the unit. The fastener assembly is riveted to the panel and remains with the panel so it can’t be misplaced. As the body of the fastener provides good support for the surface these are great for fibreglass panels. Another plus is an unfastened Dzus is easy to spot as it pops up when not in the locked position.
When using this style of fastener it’s best to use a spring back plate that has at least a 5/8” (15.9mm) centre hole to allow for the body of the unit. When fitting Self-Ejecting fasteners the backs of the rivets can sometimes sit on the back plate. To fix this it may be necessary to grind the backs of the rivets down or a less tidy method is to fit the head of the rivet on the underside of the panel. 1/8” rivets should be used when fitting these.