What are the main parts of a Turnlock quarter-turn fastener?
A Turnlock quarter-turn fastener is a complete fastening system made up of a stud, receptacle and often a grommet or retainer. Together, these parts create a vibration-resistant, quick-release connection that allows you to open and close panels in seconds without tools. On this page we explain the different Turnlock parts so you can select the right solution for your design.
Stud: the moving part you turn a quarter-turn
The stud is the visible, moving part of the Turnlock assembly. It passes through the panel and engages with the receptacle on the frame side. Depending on the series, the head of the stud can be a slotted head, cross-recess, wing head or a flush recessed head for a clean design. When you push and turn the stud a quarter-turn, the cam on the shank pulls the panel tight against the frame.
Turnlock offers light duty studs for thin, non-structural panels, medium duty studs for industrial enclosures, and heavy duty studs for more demanding aerospace and transportation applications.
Receptacle: the fixed anchor in the structure
The receptacle is mounted permanently to the structure or frame. Inside the receptacle body are the spring and the mating cam profile that lock onto the stud. Because the receptacle is hidden behind the panel, it can be welded, riveted or screwed in place, depending on your material and required holding strength.
Choosing the correct receptacle is key for reliable performance: floating receptacles compensate for misalignment, while rigid receptacles give very accurate positioning of the panel.
Grommet and retainer: protecting the panel
Many Turnlock assemblies also use a grommet or retainer on the panel side. These parts center the stud in the panel hole, protect softer materials such as aluminium or composites, and keep the stud captive so it cannot fall out when the panel is opened. This improves ergonomics for the operator and prevents foreign object damage (FOD) in critical equipment.
Spring: constant clamping force and anti-vibration
The spring inside the receptacle ensures that the panel is always clamped with a consistent force. It compensates minor tolerances in panel thickness and keeps the assembly tight, even under vibration. This is one of the reasons why Turnlock quarter-turn fasteners are widely used in aerospace, transportation and high-end industrial equipment.
How to choose the right Turnlock parts
To select the correct Turnlock parts, start with the panel thickness, required tensile and shear strength and the environment in which the assembly will be used (indoor, outdoor, corrosion-resistant materials, etc.). Then choose the duty range:
- Light duty Turnlock – for access panels, covers and enclosures in lighter applications.
- Medium duty Turnlock – for industrial machinery, HVAC, electrical cabinets and similar equipment.
- Heavy duty Turnlock – for demanding aerospace, railway and off-road applications where higher loads and vibration are present.
Our engineers can help you match the correct stud, receptacle and accessories to your application so you get the right grip length, head style and material combination from the start.
Need help with your Turnlock design?
If you are not sure which Turnlock parts you need, send us your panel drawing or application sketch. We will review your design, propose a complete Turnlock assembly and advise on installation and panel preparation. Contact an engineer today and avoid costly redesigns later in your project.