Position-retaining slot nuts
Spring Nuts for 20, 30, 40 and 45 Series Profiles
A spring or leaf holds the nut in position inside the slot while brackets, sensors, panels and accessories are aligned and fastened.
Product overview
Spring Nuts for 20, 30, 40 and 45 Series Profiles
A spring nut adds a retaining leaf or spring element to a threaded slot nut. Once inserted, the spring applies light pressure against the extrusion cavity so the nut remains near the chosen position instead of sliding freely. This is useful on vertical profiles and during assemblies where several attachments must be aligned before tightening.
Longjin manufactures spring nuts for common 20, 30, 40 and 45 series profiles with M3-M8 threads in carbon steel and 304 stainless steel. The nut body, spring direction and available cavity space must all match the target extrusion. Similar names such as leaf-spring nut, retaining nut and spring-loaded T nut do not guarantee interchangeability.
How to select
How to select
The spring controls positioning while the nut body carries the joint load. Check both parts of the interface.
- 01
Confirm the opening and cavity
Share a profile cross-section or measured dimensions so the body can enter and the spring has suitable preload space.
- 02
State the loading direction
Explain whether the part slides from the end or loads through the opening, and whether the profile is horizontal or vertical.
- 03
Match the thread and attachment
Select M3-M8 from the mating screw, attachment hole and required thread engagement.
- 04
Define the service environment
Humidity, cleanliness and appearance requirements guide the material and surface finish.
Applications
Applications
- Sensors and limit switches
- Panels and machine guards
- Attachments on vertical profiles
- Cable channels and guide rails
- Adjustable workstation accessories
- Post-assembly frame extensions
Manufacturing & quality control
Manufacturing & quality control
Inspection covers body dimensions, thread acceptance, spring orientation and resilience, insertion behavior and surface condition. Fit and position retention can be approved with a sample in the specified extrusion before production.
Share the profile series, slot width, thread, material and quantity so we can help confirm the right part.- 1
Review the extrusion slot
- 2
Confirm spring style and thread
- 3
Test sample installation
- 4
Run production and in-process checks
- 5
Inspect spring action, thread and finish
FAQ
Frequently asked questions
How is a spring nut different from a standard T-slot nut?
A spring nut includes a retaining spring or leaf that helps hold its position during assembly. A standard T-slot nut normally slides freely and may need to be loaded from the profile end.
Is a stronger spring always better?
No. The preload should retain position without preventing installation or adjustment. It needs to be matched to the target cavity.
Are all spring nuts for 40 series profiles interchangeable?
No. A 40 series profile may use different slot openings and internal cavities, including slot 8 and slot 10 systems. Confirm the actual section.
Longjin
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Send an inquiry
Share the profile series, slot width, thread, material and quantity so we can help confirm the right part.