Open-End vs Closed-End Rivetnuts
Open-end and closed-end rivetnuts both provide a threaded fixing in thin materials and can be installed from one side. The main difference is the end of the insert: an open-end rivetnut has a through-hole, while a closed-end rivetnut has a closed base.
Open-end rivetnuts
Open-end rivetnuts allow the bolt to pass through the end of the insert. They are a practical choice for many general engineering, sheet metal fabrication and machinery applications where a closed base is not required.
- Allow flexibility in bolt length, provided there is sufficient clearance behind the insert.
- Suit a wide range of general fastening applications.
- Leave a path through the insert, so they should not be relied on to prevent moisture or contaminants passing through.
Closed-end rivetnuts
Closed-end rivetnuts have a closed base that blocks the passage through the end of the insert. They can be useful where this additional barrier is required, such as certain enclosure, vehicle and outdoor equipment applications.
- Provide a barrier at the base of the insert.
- Limit how far a bolt can enter, making the correct bolt length important.
- May form part of a sealing solution, depending on the insert design and installation.
A closed end does not automatically make the complete fixing watertight. Moisture can still enter around the insert's interface with the parent material. Where sealing is essential, check the manufacturer's specifications and any requirements for seals or sealant, and test the assembled fixing.
Quick comparison
| Feature | Open-end | Closed-end |
|---|---|---|
| Insert base | Open through-hole | Closed base |
| Bolt length | Can extend through the insert, subject to clearance | Must fit within the available internal depth |
| Barrier through the insert | No closed-end barrier | Closed base blocks the through-path |
| Sealing requirements | Requires an application-specific solution | Complete joint sealing must still be verified |
Which type should you choose?
Choose an open-end rivetnut when a through-hole is acceptable and you need a straightforward threaded fixing. Consider a closed-end rivetnut when the application requires a closed base or a barrier through the insert.
For either type, confirm the thread size, grip range, material, body shape, hole dimensions and installation tool compatibility. Check the technical data for the specific insert rather than assuming either design is suitable for every application.
Need help choosing?
Contact Rivetnut Technology Systems with your material type, material thickness, thread size and any sealing requirements to discuss suitable options.