Insights - Case Study
Enhancing Worker Safety and Ergonomics in Door Assembly
Insights - Case Study
Enhancing Worker Safety and Ergonomics in Door Assembly


ITW innovation engineers help Toyota improve production team ergonomics and take fastening to a new level.

Challenge is here again

Toyota’s passion is “giving people the freedom to explore their world and reach their full potential.” They put as much care into worker safety as they do into creating dependable vehicles that offer inspiring design for Toyota drivers.

Toyota’s Health and Safety engineering staff actively seeks innovative technology and solutions to enhance job ergonomics for its production teams. Toyota’s Health and Safety engineering staff identified an opportunity to improve working conditions by reducing the required fastener installation force in door trim assembly. They sought a solution that would enhance worker safety, improve ergonomics, and maintain Toyota’s high-quality standards.



ITW Innovation Engineering worked closely with Toyota Heath and Safety, Assembly and Program Engineering using ITW’s Customer Back Innovation (CBI) process to understand the core pain points driving ergonomic challenges on the assembly line. Through the CBI process, the team discovered other opportunities to enhance the assembly process and improve performance, like increasing long-term water sealing at fastening points to enhance Toyota’s already high-quality vehicles.

ITW was able to resolve multiple fastening challenges for Toyota with a new, innovative clip – the CenterLok™ Ergonomic Fastener. Using a unique “force triangle” design, ITW Innovation Engineering solved Toyota’s primary concern by substantially reducing required insertion force. Concurrently, ITW was able to engineer additional retention force into the clip once it was seated, increasing the stability of the attached trim. Adjusting the design approach to the fastener clip “arms” created better angular compensation during insertion and removal of the CenterLok™ clip, further improving ergonomic performance if the door panel needed to be removed for service.

A unique overmold elastomer seal on the CenterLok™ dramatically enhanced sealing at fastener points – an additional benefit identified as a target by ITW during the CBI discovery process.


ITW’s CenterLok™ fastener exceeded Toyota’s target expectations by reducing the average insertion force for vehicle door system assembly by approximately 45%. Concurrently, the CenterLok™ design improved long-term water sealing at fastening points up to 200%, depending on application area.

Insertion Force – 45%

Water Sealing at Fastening Points up to + 200%
(depending on the application area)

The Toyota team was pleased enough with the results to nominate ITW Automotive for the prestigious Toyota Excellent Technology & Development Award.


After experiencing benefits of the CenterLok™ fastener in the vehicle door system, Toyota expanded use of the new fastener into multiple interior and exterior applications. Toyota has implemented the CenterLok™ across numerous vehicles, including the Camry, RAV4, Sienna, Highlander, Corolla Cross, and Tundra, as well as the RX from Toyota’s premium Lexus brand. The CenterLok™ fastener has been implemented in Toyota plants across Europe and North America.

ITW’s CenterLok™ Ergonomic Fastener was a recipient of the 2022 Toyota Excellent Technology & Development Award.

Toyota works collaboratively with each supplier partner to ensure our vehicles meet the high-quality, safety and reliability standards our customers expect,” said Robert Young, Toyota Motor Engineering & Manufacturing North America’s purchasing supplier development group vice president. "We are pleased to award those in our supply base who exceed our expectations."

To learn more about CenterLok™ or ITW Automotive’s innovation capabilities, use the Contact button below.

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