What Is Riveting. How Is It Done?

In our machine technology manufacturing processes – machine elements lessons, we’ve dedicated this article to riveting.

What Is Riveting

A rivet is a cylindrical element with one end already formed and the other end shaped during assembly, used for permanently joining machine parts, sheet metal, and machine elements such as belts and brake linings.

The process of joining parts with elements called rivets is called riveting. The purpose of riveting is to create a permanent joint.

We especially encounter rivets in steel construction buildings and ships.
They’re used in machine tool manufacturing, the maritime industry, the construction industry (especially steel structures), the locomotive industry, the apparel sector (jeans, belt manufacturing, etc.), and kitchenware (such as handle attachments on household items like kettles and pots).

In fact, we encounter riveted joints in many areas of everyday life.

Before the development of welding technology, rivets were used to join large sheet metal components—particularly in the construction and shipbuilding industries. Early 20th-century vessels, such as the Titanic (1912), were entirely riveted (it is estimated that approximately 3 million rivets were used on the Titanic).

Observations from that era also noted that riveted hulls behaved somewhat more “flexibly” in rough seas compared to modern welded hulls. As welding technology began to advance in the late 1930s and its advantages over riveting became apparent, the use of rivets in these structures was gradually phased out.

How Is Riveting Done

Blind Rivets (Pop Rivets)

This is the process done with special-type rivets whose head isn’t shaped by hammering.

This is riveting done using a blind rivet. It consists of two parts called the rivet mandrel (pin) and the rivet body. The body is made of a soft material, and the mandrel is made of steel. Used in places where there’s only access from one side.

The rivet mandrel sits inside the body. The mandrel’s end that’s mounted in the hole and remains outside is pulled with the pulling tool. As a result of pulling, the end of the mandrel that snaps off at the notched section is discarded. The head of the mandrel remains inside the body. This is how the rivet’s second head is formed. (video above)

Explosive Rivets

A rivet with an explosive capsule placed inside its body. A hot punch pressed onto the rivet head detonates the capsule. As a result of the explosion, the rivet head is formed. Used for joining aluminum and aluminum alloys.

Rivet Types Used in Riveting

Various rivet types are used depending on the nature of the riveting to be done. These are:

Round-head rivet
Countersunk-head rivet
Lentil-head rivet
Cylindrical-head rivet

Rivet materials: Rivet materials generally match the type of the parts to be joined. The main rivet materials are steel, iron, aluminum, copper, and brass.

Calculating Rivet Diameter and Length

For thin sheets, the rivet diameter is taken as 2 times the sheet thickness (S).
For thick sheets, rivet diameter d = sheet thickness + 8 mm.
The rivet length to form the driven head is taken as ……………… l = 1.5 d. To prevent the rivet holes from misaligning, the parts should be clamped together and drilled together.

For countersunk-head (flush) riveting, the rivet length to form the hidden driven head should be at least twice the countersink depth (h), h = 2 h.

To prevent the rivet holes from misaligning, the parts should be clamped together and drilled together.

The Riveting Process

Drilling rivet holes and countersinks:

Rivet holes are drilled 0.1-0.2 mm larger than the rivet diameter (d), and the hole edges are countersunk with a 90° countersink drill. This ensures the rivet seats well and easily.

2 — Cold and hot riveting:  Applied to small-diameter rivets (generally up to 8 mm diameter). If necessary, the materials are annealed before riveting.

As rivet diameter grows, the forming (hammering) process becomes more difficult, so large-diameter rivets and rivets in places requiring sealing are formed using the hot riveting process.