Rivet Types
There are five families of Henrob self-pierce rivets. Each family is defined by unique geometry and has a range of macro features including head style, stem diameter and stem length. The five groups have been specifically developed to meet different functional requirements and application performances.
Rivet Type Selection
The choice of rivet type for a given application is dependent on numerous performance criteria - see Joint Development for details. A rivet is selected, in conjunction with appropriate tooling, to match the application characteristics such as the examples listed below:
| Typical Application Characteristics | Examples |
|---|---|
| Material Types | Aluminium, Steel, Plastic, Composite |
| Material - High Ductility | Cold rolled steel sheet, Alu Sheet |
| Material - Reduced Ductility | Hot rolled steel, Extrusions, Castings |
| Material - Low Tensile Properties | Mild steel, Non ferrous alloys, Plastic |
| Material - High Tensile Properties | HSLA steel, DP & TRIP steels |
| Total Joint Thickness |
1mm to 6mm (Steel) 1mm to 10mm(Alu) |
| Mixed Material Combinations | Plastics to metal, Alu to steel |
| Structural | Vehicles, Buildings |
| Non-Structural | Furniture, Cabinets, Attachments |
Head Styles
Head styles are selected on the basis of either functional requirements or aesthetic appeal. Functional requirements may be:
- Head flushness (level with material surface)
- Shear, peel and fatigue strength
- Locator or mechanical stop
- Large bearing surface
- Attachment points for secondary parts
Countersunk Head
Benefits:
- Flushness on the head side of the joint
- Good fatigue resistance
Flat, Pan and Dome Head
Benefits:
- Provides good peel strength, especially in plastics or thin sheet metals
- Allows good head seating, especially when riveting thick or very hard materials
- Accentuates the aesthetics of a riveted joint and/or covers surrounding indentation on a Class A surface
Special Head Styles
Special rivet head styles are supplied when there is a need to combine the functions of the self pierce rivet and an additional feature.
Rivet Length & Stem Diameter
Rivet length is always matched to the stack thickness to be fastened. A given rivet length will cover a range of material stacks. Testing is carried out to determine the suitability of the rivet length for the material and thickness range being riveted. Henrob offers rivets in lengths of 4 to 14mm.
There are two standard diameters, 3mm and 5mm. The criteria for selecting the appropriate rivet diameter includes:
- Required strength of joint
- Required robustness of joint
- Available access to joining area
- Material thickness and hardness