The usual fastening of blade shafts to the handle consists of rivets. Usually seven to ten millimeters thick, the shank diameters fix the blade in two, sometimes three places. The biggest advantage over screws is the flat rivet head. Rivets are usually made of aluminum, stainless steel or brass.
Structure of rivets
In principle, a rivet is a kind of tube that is spread by force in a hole or channel. The rivet protrudes on both sides of the handle part to be connected. When the rivet is closed, the two ends of the tube “burst open” in the shape of a crown and form a stable connecting element.
Rivets are also used in pocket kn ives and folding knives. Here, however, they represent the connection between the handle scales and the blade bed. Special rotary rivets can also form the movable joints between the blade and the tang.
Hollow and pin rivets
The tubes of the rivets can be made hollow or solid inside. Hollow rivets produce less holding power and stability than pin rivets. However, hollow rivets are easier to work with and to replace or reset.
If particularly durable riveted joints are to be created, the hollow rivets are additionally “glued in” with synthetic resin. In some cases, upsetting is not used in this construction method. In this case, the rivet represents an embedded reinforcement.
Driving in rivets and flattening the head
There is a simple rule of thumb for setting and upsetting a rivet to make it fit and last. The diameter of the rivet should be one millimeter smaller than the hole in the blade shank. On both sides, the rivet should extend 1.15 times its own diameter beyond the handle holes.
There are simple rivet setups that are inserted using only “brute” force. The knife handle with the bottom rivet end protruding at the proper height must be placed on an impact-resistant surface such as an anvil. A hammer is then used to “flatten” the rivet. For straightening the rivet heads, so-called rivet head setters are used, also known as döppers.
Tips & Tricks
If you make a knife yourself, you can choose from various rivet head shapes. However, you will then need the appropriate rivet head setter to create a flat rivet head that does not protrude when using the knife.