A rivet gauge tool is used to measure the diameter and length of rivets and rivet nuts.
Place the rivet or rivet nut into the matching slots or holes on the gauge.
The correct fit indicates the proper size for selection and installation.

How To Measure Rivets & Rivet Nuts Using a Rivet Gauge Tool

A rivet gauge tool is a measuring tool used to determine the size of rivets and rivet nuts, including parameters such as diameter, grip range, shank size, thread size, and length. Correct measurement is important because selecting the wrong rivet or rivet nut can lead to weak joints, poor fit, assembly problems, or structural failure.

Measuring with a rivet gauge is commonly done in manufacturing, sheet metal work, maintenance, and fastening applications.

Understanding the parts to be measured

Before using a gauge, understand what dimensions are important.

For rivets, common measurements are:

Shank diameter
Rivet length
Head diameter
Grip range
Head style

For rivet nuts, measurements include:

Body diameter
Thread size
Grip range
Body length
Head type

Parts of a rivet gauge tool

A rivet gauge typically contains:

Diameter holes

Used to identify rivet diameter.

Examples:

2 mm
3 mm
4 mm
5 mm
1/8 in
3/16 in
1/4 in

Thread gauge section

For rivet nuts:

or inch thread sizes.

Grip thickness scale

Measures material thickness range.

Length markings

Used for rivet body length measurements.

Identification chart

Some gauges include conversion tables and standards.

Measuring rivets using a rivet gauge

Step 1: Clean the rivet

Remove:

Dirt
Oil
Burrs
Debris

This improves measurement accuracy.

Step 2: Measure rivet shank diameter

The shank is the cylindrical body of the rivet.

Procedure:

Insert the rivet shank into different diameter holes.
Find the hole where it fits closely.
The matching size is the rivet diameter.

Example:

If the rivet fits snugly into a 4 mm hole:

Rivet diameter = 4 mm

The fit should not be:

Too loose
Forced tightly

Step 3: Measure rivet length

Length is measured from:

Under the head to the end (for protruding head rivets)
Entire length including head (for countersunk rivets)

Procedure:

Place rivet on gauge scale
Align head properly
Read the length marking

Example:

Measured length:

12 mm

Step 4: Identify head type

Common rivet heads:

Round head
Snap head
Flat head
Countersunk head
Dome head

Head shape influences measurement reference points.

Step 5: Determine grip range

Grip range is the total material thickness the rivet can securely fasten.

Procedure:

Measure combined sheet thickness
Compare with gauge chart

Example:

Two plates:

2 mm + 3 mm

Grip thickness:

5 mm

Choose rivet with matching grip range.

Measuring rivet nuts using a rivet gauge

Rivet nuts require additional measurements because threads are involved.

Step 1: Measure body diameter

Insert the rivet nut body into gauge holes.

Find the closest fitting size.

Example:

Fits in:

8 mm hole

Body diameter:

8 mm

Step 2: Measure thread size

Use the threaded section of the gauge.

Procedure:

Try different thread gauges
Find correct thread engagement

Examples:

The correct size screws in smoothly.

Step 3: Measure grip range

Rivet nuts work over specific material thickness ranges.

Measure:

Total thickness of material

Then compare with:

Manufacturer grip range chart.

Step 4: Measure rivet nut length

Place the rivet nut against the gauge scale.

Read:

Body length
Total length

Example measurement procedure

Suppose a blind rivet is measured:

Shank diameter:

4.8 mm

Length:

14 mm

Material thickness:

6 mm

Result:

Rivet specification:

4.8 × 14 mm rivet

Common mistakes during measurement

Measuring the head instead of the shank

Incorrect because diameter is based on shank size.

Using damaged rivets

Deformed rivets give incorrect readings.

Ignoring grip range

May result in poor fastening.

Wrong measurement reference

Countersunk and protruding heads use different references.

Forcing the rivet into gauge holes

Can create inaccurate measurements.

Advantages of using a rivet gauge

Fast identification
Accurate sizing
Reduces assembly errors
Helps select correct rivets
Useful in maintenance work
Simplifies inventory management

Applications

Rivet gauges are used in:

Aerospace industry
Automotive manufacturing
Sheet metal fabrication
Machinery assembly
Construction
Maintenance workshops

Conclusion

A rivet gauge tool helps accurately measure rivet and rivet nut diameter, length, thread size, and grip range. Proper measurement ensures correct fastener selection, stronger joints, and reliable assembly performance. Careful use of the gauge reduces installation errors and improves fastening quality.