Multi-Grip Blind Rivets
What Is a Multi-Grip Rivet?
Multi-grip rivets are an outstanding alternative to standard-grip rivets. Though standard-grip rivets are often solid in their own right, a project may require something with more versatility and efficiency. They provide incredible versatility for your project. They fit as extensive range of grip sizes so that if thickness differs somewhat, whether thinner or wider, the rivet can accommodate the variance.
From a fastening standpoint, multi-grip rivets can help address precision needs. These rivets offer versatility in that they can be set in a variable grip range depending on the combined thickness of the two materials being fastened. In other words, the same rivets can be used for one application, even if the surface gets a little thinner or thicker.
Multi-grip rivets offer other benefits, including:
- Better hole fill: Multi-grip rivets expand radially to deliver a better fit, even with irregular, oversized, and misaligned holes.
- Added weather resistance: Moisture is less likely to seep through the setting because of the better hole fill.
- Better inventory management: Multi-grip rivets generally fit three different grips; stocking one rivet for three grips—rather than three separate rivets for three sizes—streamlines inventory and makes ordering online easier.
- Aesthetic consistency: If an application has several different rivets populating a small area, the resulting hodgepodge may detract from the product’s appearance, particularly with consumer goods. Multi-grip rivets offer a uniform look.
- High vibration resistance: The improved hole fill results in joints that better withstand vibration.
Multi-grip rivets are ideally used for projects in which the materials’ thickness varies—even where rivets are within a short distance of each other. They also better fill oversize holes for stronger fastening. Multi-grip rivets are often used for the following projects: automotive, domestic appliances, electronics, electrical equipment, light industrial, and HVAC.
Pros and Cons of Multi-Grip Rivets
The versatility of multi-grip holes is unmatched. They typically cover three grip ranges, so as the thickness of a section of the material’s structure begins to vary, you won’t be scrambling to find the right rivet. These rivets expand radially, thus resulting in greater hole fill and providing a cleaner final set.
Because projects won’t require so many specific sizes of standard rivets, ordering becomes simpler, and you are less likely to run out of a certain size. Also, aesthetic consistency improves because an area isn’t populated with several different types of rivets.
However, multi-grip rivets take longer to apply; this is countered by a stronger fit and less effort to toggle between different sizes. And regarding pricing, multi-grip rivets are generally more expensive than standard-grip rivets. Cost is offset by reduced labor—work interruptions decrease because you always have a usable rivet on hand and the resources needed to manage rivet inventory.
Head Styles
Dome Head
The Dome Headed or sometimes called Round head blind rivet is the most versatile and commonly used type whose lower profile head is approx. twice the diameter of the rivet body. This provides adequate bearing surface for nearly all applications where metals are being joined.
Aluminium – Steel Download-Datasheet AL-ST
Aluminium – Stainless Steel Download-Datasheet AL-SS
Steel – Steel Download-Datasheet ST-ST
Stainless Steel – Stainless Steel Download-Datasheet SS-SS
CSK Head
The Countersunk or CSK head profile provides a neat and flush finish to the joint. This enables multiple layered assembly and also a safe surface without any projection.
Aluminium – Steel Download-Datasheet AL-ST
Large Flange
Aluminium – Steel Download-Datasheet AL-ST
Galvanic Corrosion
When dissimilar metals come into contact in the presence of an electrolyte, a galvanic action occurs which corrodes one metal at a faster rate and the other more slowly. This phenomenon can cause major riveted joint failures and care must be taken to avoid the occurrence. The following table is a guide.
| METAL JOINED | |||||
| RIVET MATERIAL↓ | Aluminium | Coated Steel | Stainless Steel | Copper | Brass |
| Aluminium | YES | CARE | NO | NO | NO |
| Coated Steel | NO | YES | NO | NO | NO |
| Stainless Steel | CARE | CARE | YES | YES | YES |
| Copper | NO | NO | YES | YES | YES |
| Monel | NO | NO | YES | YES | YES |
| YES | Compatible | ||||
| NO | Incompatible – Avoid contact with each other | ||||
| CARE | Use with care. Painting metals will help | ||||
Hence,
1) Select materials that are as close together as possible in the Galvanic Series Chart
2) Provide a barrier between the two metals, such as paint, non-metallic washer or gaskets
3) Design the fastener as the cathode so the cathodic area is small as compared to the anodic area
4) Use a metallic finish on the fastener that is close on the chart to the mating material