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How can fastening technology optimise the design of the Body in White (BIW) for EVs?

With the design of the Body in White (BIW) of Electric Vehicles (EVs) demanding even greater performance from fasteners than internal combustion engine (ICE) vehicles ever did, partnering with an experienced and innovative automotive fastener manufacturer has never been more important. EJOT’s Steve Wynn, UK Sales Manager for Industrial Fastening Solutions, explains why.

The BIW’s structural stability and reliability is key to guaranteeing passenger safety in every type of vehicle, which is why decisions regarding materials and fasteners for this area of the vehicle are particularly important.

For EV designers, however, there are additional goals for the BIW. It must still offer a high tensile strength, as well as high stiffness in respect of bending, torsional, static, and dynamic strength, while at the same time being lightweight, corrosion resistant and enabling the secure integration of the EVB. All this without compromising the need for easy assembly and disassembly.

One of the ways the EV industry has been able to create BIWs that meet these complex and seemingly contradictory objectives is through utilising advanced fastening systems, including those from EJOT.

EJOT has been at the forefront of fastening systems for the automotive industry for decades, with our solutions helping to facilitate manufacturers’ shift to hybrids and first generation EVs. Our innovative approaches to joining lightweight materials have been key to vehicle weight reduction goals, initially helping manufacturers around the world to deliver significantly better fuel efficiency in ICE vehicles, and now benefitting EV and hybrid vehicle designs.

Continuous Product Development 

Driving EJOT’s continuous product development programme has been the ‘build lighter, build stronger’ ethos, which is important for the BIWs of EVs given the overall vehicle weight gain that the batteries are likely to add. This is one of the reasons why we are seeing increased use of new forms of steel rather than aluminium or composites.

But we also have to consider the fact that the battery pack will form a structural part of the BIW. This is why the excellent performance characteristics of EJOT fasteners can add more value than ever.

Typifying this is the EJOT FDS or “Flow Drill Screw”. This is proving of great value to EV manufacturers given its suitability for single sided applications, as no supporting anvil is needed, and its multi-material joining capability.

The EJOT FDS® is a flow drilling screw for high-strength sheet metal joints. This reduces the need for additional processes in both the clamping material and installation boss material, which means reduced need for alignment and savings in handling time during BIW assembly.

Another solution that is ideally suited for BIW applications is EJOT EJOWELD, an innovative system for joining different materials and semi-finished parts backed by a full application support package. It provides a way to join multi-material designs, especially lightweight materials such as aluminium and advanced high-strength steel, with a friction element setting tool which is suitable for robot assembly.

Using specially designed EJOT components, a thermomechanical process makes use of energy generated through the rotary function between the joining element and the base plate to create an incredibly strong weld in a four stage assembly process that takes less than a second. And it is proven in the market too, with EJOWELD used by one premium UK vehicle manufacturer for joining key areas of the BIW.

The Benefits of EJOT Components 

The versatility of the EJOT fasteners to work consistently in multiple areas of the BIW’s assembly means that FDS, EJOWELD and other fasteners in the range, can lead to a reduction in the parts needed. But this is not the only benefit possible from a production perspective – EJOT fasteners additionally offer simpler installation and an engineering quality that means greater reliability of installation equipment. This is crucial to ensuring “Takt times” are met.

BIW designers can also benefit from EJOT’s specialist technical support, which provides valuable support in the development process to enable demanding performance criteria to be met whilst also delivering savings in terms of time and costs. From easy access to CAD drawings and online tools to project support from EJOT application engineers in both the UK and Germany, it is a package that can be used throughout the design, testing and deployment stages.

Common benefits exist across all the EJOT fastening solutions for BIW. From solutions which take the form of lightweight material fasteners, fixings for composites, screws for aluminium and multi-materials, to self-drilling, plastic, removable and special application fasteners, thread formers, self-tappers or flow drill screws, the EJOT brand can be trusted to deliver.

What to know more? Read about the fasteners featured in this article:

  • FDS® - For high-strength sheet metal
  • EJOWELD - Friction welding for demanding automotive structural engineering

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An illustration of the different phases during insertion of the EJOT FDS screw, which is ideal for BIW applications on all kinds of vehicles.

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BIW construction is an area where EJOT has particular expertise and that extends to meeting the challenges in EV design and manufacturing.


EJOWELD is an innovative friction welding system for joining different materials and semi-finished parts featuring a friction element setting tool which is suitable for robot assembly.