How to install M22 signaling devices

Signaling devices with an M22 thread are primarily installed in control panels. They are used, for example, to visually indicate the operating status on the control panel door. But they are also used on special vehicles. This article explains how to install M22 signaling devices in the best way.

Useful tips for the installation of signaling devices with M22 threads

Although the installation of M22 devices is quite fast and easy, we recommend having a look at the following three tips:

  1. Make sure the metal blade directly on the plastic nut has the claws facing the surface of the mounting surface. The claws ensure high surface pressure and elastically preload the gasket. This ensures permanently secure mounting of the signaling device even under the most adverse conditions of vibration and/or temperature variations. Even settling of the seal due to incorrectly slightly increased pretension during assembly or aging can be compensated.

  2. Pay attention to the specified tightening torque of the union nut during installation. Excessive pretensioning can squeeze the seal and, over a longer period of time, lead to a reduction in the degree of protection (suitability against environmental conditions such as water ingress) due to material and/or temperature-related creep of the elastomer seal.

  3. Our panel-mount devices have already proven themselves for decades as ideal M22 signaling devices in harsh conditions. To ensure their protection type, we recommend checking the mounting holes for freedom from burrs before mounting.


Our signaling devices with M22 thread have an installation dimension of 22.5 mm. Due to this common installation dimension and the low installation depth, a built-in device from Auer Signal can be installed easily and uncomplicatedly as a single-hole installation, even in tight spaces.

The exact dimensions can be found on the respective product page or in the instruction manual. The drawings below show the dimensions and installation guide of our ICM M22 panel mount LED multi strobe beacon.


                    Dimension drawing M22                Installation drawing M22



What does M22 mean?

M22 stands for a thread according to the ISO metric thread. The letter "M" indicates that it is a metric thread. The number 22 specifies the size designation (diameter) 22 mm. In the ISO metric thread standard, information on the diameter is given in millimeters.

If the thread designation consists only of the letter "M" for metric and the size designation 22, it is referred to as a standard thread. However, if there is an additional specification such as x 2.00 or x 1.5 after the size designation, it is referred to as a thread with thread pitch (P):

  • Threads with a thread pitch that is smaller than the standard thread are called fine threads.
  • Threads with a pitch greater than the standard thread are called coarse threads.


The term M22 is used for external threads (screws, threaded rods) but also internal threads (nuts, socket threads).


What is the size of a M22 thread?

This table shows the standardized size of M22 threads according to the ISO metric thread standard.


M22 metric thread
Major diameter 22.00 mm
Pitch  2.50 mm
Pitch diameter 20.376 mm
Minor diameter
Male Thread
18.933 mm
Minor diameter
Female Thread
 19.294 mm



What is the diameter of an M22 thread?

The nominal diameter for an M22 female and male thread is 22.00 mm. This diameter is specified in the metric ISO thread standard. In our dimensional drawings of the panel mount products, you can recognize the dimensions of an M22 thread by the corresponding designation "M22".


What does M22 x 1.5 mean?

The specification M22 x 1.5 refers to an M22 thread with a thread pitch of 1.50 mm. Since the thread pitch is smaller than standard threads (2.50 mm), this is a fine thread.


Advantages of devices with M22 thread

The M22 installation dimension is the standard installation dimension in control panel construction. Thus, there are not only signaling devices with this installation dimension, but also many other industrial components that are required for a control panel. These include pushbuttons and switches. For this reason, switch panels or empty housings with M22 pre-drilled holes are often used in these application areas. However, the installation of a complete control panel system is also greatly simplified if all industrial components have the same installation dimension. With an M22 tapping set, the appropriate drill holes can be drilled or punched quickly and easily.


Our Series M22 – the Installable

Our built-in series M22 - the Loudest & the Brightest Installable - is available as visual, audible and visual-audible signaling device in three sizes (Ø 30 mm, Ø 45 mm and Ø 65 mm). The M22 series is characterized by its versatile functions and application possibilities.




Our built-in buzzers ESK and ESV are particularly characterized by their good price-performance ratio. They are available in two different housing colors, black and gray. Despite their small size Ø 30 mm the ESK and ESV convince with their volume. ESK reaches a volume of max. 65 dB, the ESV built-in buzzer even max. 85dB. The product portfolio of the built-in buzzer is completed by the ESM and ESG. Our piezo buzzers are the loudest built-in buzzers on the market with max. 103 dB.



Our M22 built in beacons score with a high lateral and frontal luminosity and signaling effect. The beacons are particularly durable and resistant to vibrations thanks to the high degree of protection IP65 and IP67 for pre-wired models. The built in beacons are available with the functions: steady/flashing, strobe/multi-strobe, xenon strobe and multicolor steady light in six different colors.

A special function of the M22 series can be found in the ITS, ITM and ITL models. These models can display two different colors. The lens consists of two separate color areas. Thus, this beacon can display two colors simultaneously or only one of the two colors. Other color combinations are available upon request specifically for your application.




The visual-audible devices combine the functions of a built-in buzzer and a beacon. The piezo buzzers with LED beacon (Ø 45 mm and Ø 65 mm) are available as LED steady light or LED steady/flashing light in the colors orange and red.