A heavy-duty truck grab handle is one of the last components added to a tractor before it comes off the assembly line. But it’s one of the most important because drivers rely on it every day.
Because drivers come into contact with it every time they climb into their cab, a truck grab handle is one of those heavy truck parts that has to “feel right.” And if it doesn’t, it can become one of those things that bothers a driver whenever they set out on their next ride.
A poorly engineered truck grab handle can also irritate a driver while out on the open road. If a grab handle isn’t aerodynamic, it will produce wind noise when the truck it’s attached to runs at high speeds. This resistance can even affect fuel economy — a major consideration for all truck drivers.
Taking all these factors into account, how exactly do you create a truck grab handle that truck drivers will appreciate?
Working with a client of ours, we set out to answer that question. Here’s what we learned and how we ended up creating the first hydroformed heavy truck grab handle on the market — a feat that managed to earn us an award.
Finding the Right Shape
Our customer had been making cabs with truck grab handles that were just round stainless steel tubes for years. While they looked nice, they could get a little slippery and weren’t aerodynamic at all. Drivers had started complaining about wind noise at 55 mph and above.
To help with the noise issue, they wanted to give the truck grab handle a teardrop shape in cross section — much like an airplane wing.
While this was a great design solution, it didn’t seem feasible given the quantity, price target, and production requirements the OEM wanted to achieve. The quantities weren’t high enough to justify tooling for tubular stamping, which could have made the acutely sharp corner that defines the teardrop shape.
As an experienced handles manufacturer, our recommendation was to adjust the design to an oval shape and use tube hydroforming. The oval shape was sufficiently aerodynamic to neutralize the wind noise and could be made easily with hydroforming. This allowed us to keep tooling costs at a minimum and to deliver quantities in the tens of thousands as cost effectively as possible.
Choosing tubular hydroforming also enabled us to introduce a design variation our customer hadn’t anticipated — finger grips. Because hydroforming allows for the creation of complex, asymmetrical shapes, we were able to add a knurled texture to one side of the truck grab handle that enhances a driver’s ability to grip it.
Minding the Manufacturing Details
Once we decided on a basic approach to production, we needed to figure out how to meet the constraints provided by the customer.
At 51 inches long, the handle was much longer than typical tubular hydroformed handles. At first, we thought this would be a challenging issue to overcome but quickly determined that there were no issues with creating the desired shape and retaining the required strength.
Once we had the basic shape perfected, we began looking for ways to optimize the production process.
Originally, the plan was to create separate dies for left and right handles. We managed to devise a process wherein only a single die was needed for the hydroforming press. Instead of hydroforming two different pieces, we created a single piece and then cut it differently depending on whether it was a left or right handle. This modification reduced our customer’s tooling costs significantly.
Surprisingly, perfecting the hydroforming process was relatively easy. More challenging than expected was figuring out how to weld the product to the plates that would be used to attach it to the truck cab.
The customer had very exacting requirements for these welds. They had to be nearly invisible but also have great penetration and support over 500 lbs. of pull strength. The welds also had to be executed in one motion with no stopping once you started welding.
We knew right off the bat that we would have to use our robotic welder to meet the specifications and replicate the weld consistently. It took us nearly four months of trials and testing using different speeds and gases before we finally hit on the right combination, which can withstand several thousand pounds of pull force.
A Truck Grab Handle That Makes a Difference for Drivers
One of the advantages of hydroforming is that we were able to use it to produce a short run of prototypes for testing before entering full production. Our customer took advantage of this opportunity to add early iterations of the truck grab handle on tractors for road testing. As designed, the handles produced almost no road noise at high speed and were quickly put into production to meet an aggressive product launch date.
At first, the knurled, aerodynamic truck grab handle we produced was offered on OEM trucks as an option. Requests have been steadily growing as word has spread among truck drivers. Our truck grab handle seems to have hit a sweet spot, making drivers’ lives just a little better by reducing road noise and giving them something solid and secure to hold on to as they raise themselves into their cabs.
At Mills Products, we’re designers and engineers ourselves, so we understand the importance of getting a product right so that it resonates with end users. That’s why we enjoy partnering with OEMs and Tier 1 suppliers to devise economical manufacturing strategies that support new products destined to make a difference in customers’ lives.