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Electric rotor bolts are fasteners conceived only for electric vehicles.

Their particular duty is to secure the three main parts of the motor: rotor, stator, and outer armature or casing.

As explained in the section on co-moulded bolts, the electric motor has characteristics different from the internal combustion engine.

Therefore, it requires the production of specific bolts and fastening elements, also able to respond to the most innovative needs.

Even if this type concerns the latest generations of electric vehicles, in general, this sector is characterized by extremely long electric rotor bolts with special rectilinearity requirements.

These technical characteristics are already present in some critical bolts of the internal combustion engine, and here are taken to the extreme.

The know-how that Brugola OEB has developed in the automotive industry in many years of experience lays the foundation for meeting the new market requirements with expertise and quality, such as the Zero Defects and Total Quality electric motor bolts.


very long bolts with particular rectilinearity requirements

Dedicated machining

guarantee of required rectilinearity

High voltages

innovative co-moulding method


The particular assignment of electric rotor bolts is to hitch the three main parts of the motor: rotor, stator, and armature or external casing.


Electric rotor bolts are not subject to particular stresses: once the armature is tightened, the rotor makes its revolutions without mechanically stressing these bolts.

#Brugola OEB

Brugola OEB electric rotor bolts are the outcome of numerous years of experience and the greatest attention to the unique needs and specifications of each customer.
Every fastener we produce comes up to the Total Quality and Zero Defects principles.


The length of our electric rotor bolts can be over 30 times the diameter.

The main characteristics of electric rotor bolts

From the mechanical characteristics viewpoint, electric motor bolts are not put under any particular stress, because the rotor makes its revolutions without putting them into any mechanical stress.
Unlike some critical bolts of the internal combustion engine, such as the cylinder head bolts, the electric motor bolts are not subject to extreme thermal expansion.

As was mentioned, they are characterized by their length and rectilinearity.

Electric motor bolts have a diameter-to-length ratio particularly extreme. The tolerance inside the hole in which they have to be fastened is very narrow, so they must be fully straight to avoid interferences with the internal hole diameter.
Despite this need, during heat treatment, the electric motor bolts tend to deform due to their length, and for this reason, the achievement of perfect rectilinearity is the most critical part of the production phase.
To give an idea of the geometry of the electric motor bolts: their length reaches over 30 times the diameter, a very extreme ratio that by far surpasses that envisaged in internal combustion engine bolts.
To make a comparison, the cylinder head bolts of the internal combustion engine, which in turn have a critical rectilinearity ratio, usually have a length 20 times the diameter or even less.
For this reason, it is essential to carry out a series of dedicated machining and transformations to straighten the electric motor bolts during the various production cycle stages, guaranteeing the demanded rectilinearity.

Thanks to its production process optimization, today Brugola OEB can supply the market with excellent quality electric motor bolts, supported by decades of innovation and custom machining in the field of the most critical fastening elements demanded by the automotive market.

Our bolts do not allow errors or imperfections.
This is why 100% of our products are inspected at the end of the production cycle to guarantee Zero Defects, a characteristic that has always set us apart from the competition, both for productions for internal combustion engines and for electric motor bolts.

Our bolts do not allow errors or imperfections. This is why 100% of our products is checked at the end of the production cycle so as to guarantee Zero Defects, a characteristic that has always set us apart from the competition, both for productions for internal combustion engines and for electric motor bolts.

Why choose
Brugola OEB electric rotor bolts

Our company is today the leader in the design and production of fastening elements for the automotive industry.

Although having built our career on critical bolts and fasteners designed for the internal combustion engine, we have worked tirelessly to offer our customers quality products dedicated to the electric motor.

In addition to having developed an innovative method of co-moulding for those bolts safely performing even at high voltages, we have been producing electric motor bolts since 2018.

This indicates that Brugola OEB is always one step ahead of the market’s changes, investing in innovative solutions.

Our company applies the same Total Quality and Zero Defect principles that have always distinguished its historic production of electric motor bolts as well.

To attain the desired results, we support our customers with a tailored consultancy that leads us to design the geometries best suited to the application.
The initial specifications provide us with the basic parameters on which we design the electric motor bolts, and this is how the study phase to make fully customized bolts initiates.
Thanks to an in-house software program, before going into production we can conduct customized tests and simulations to understand how the electric motor bolts will behave once they are positioned.
Our customers receive detailed reports to best support their final design choice, basing their decision on the reliable data that we provide.