Hand tool manufacturers focus on ergonomics

by Clair Urbain and Paul Arnold

Blow by blow and strain by strain, construction and maintenance workers literally take a beating when they complete jobs with tools that subject their muscles, tendons and bones to the impacts and strains of everyday work. 

But help is on the way. New tools today carry effective features that help insulate users from the stresses of work. 

Recently, extensive research conducted by hand tool companies has led to improved tools. Computer-aided design and out-of-the-box thinking have produced some interesting shapes in common tools. 

For example, Danaher Tool Group, which makes Armstrong, Allen and other tool brands, uses a "voice of the customer" process to identify users' tool needs. It then develops tool designs that address those needs, says John Rossi, director of industrial marketing at Danaher Tool Group. 

"We get user input, then take it to our research and development people who come up with new designs," he says. "We have users try the concept tools for 30 to 90 days and have them tell us what they like and don't like, how it has helped them in the jobs they do and if any other modifications are needed." This research is changing the look and feel of tools. 

It's not just soft grips 
Although many of today's new tools incorporate cushy grips in their designs, not all spongy grips are indeed ergonomic. "There are many tools out there that call themselves 'ergonomic' that in fact aren't," says Gary vanDeursen, director of innovation and design at Stanley Works. "Adding cushion grips may make the tool look different, but it doesn't mean the tool is easier to use or less damaging to the body. 

Stanley spends considerable time on the physics involved with using the tool. A key component of that research is how the hand addresses the tool and transfers muscle power into mechanical power. 

At first blush, some designs seem correct, until you look closely at the dynamics taking place during the task. 

For example, adding rubber to the handle should make it easier to grip, and therefore more comfortable. But in reality, it can cause greater hand trauma when your hands are sweaty. 

"When your hand starts to perspire, you must grip the handle more tightly to maintain control," says vanDeursen. "To account for this, the grip's design must allow the skin to breathe and reduce perspiration." 

Often, tools with well-defined grips are uncomfortable to use. "We find that highly formed grips restrict hand placement on tools," says John Staton, senior designer at Stanley Works. 

"We videotaped several contractors using hammers and found that when they drive a nail, they first choke up on the handle a bit for better control, then move back on the handle for more power once the nail is started." 

The research also revealed that hammers transfer shock waves back into the hand, wrist and elbow, setting the user up for a cumulative trauma disorder. Stanley researchers then developed the Anti-Vibe hammer that transmits only one-eighth of the shock load to the body. 

New looks to old tools 
Once engineers have closely studied how users put tools to work, some interesting ideas begin to emerge, creating a total new look for some hand tools. 

Pliers are a good example, according to John Howard, design manager at Stanley Works. 

"As we watch users work with a pair of pliers, they instinctively use their ring finger inside the back of the pliers to help open and close it. So we have incorporated a soft chamfered edge into the handle of the MaxGrip to help users work more effectively," he says. 

Screwdrivers are also taking on a new look. The traditional four-lobe handle is losing popularity to a new three-lobe design, says Staton. 

"The three-lobe design with cushion grips on the lobes offers a better grip than a four-lobe design," he says. "You get better leverage." 

Danaher also offers a new line of screwdrivers with the three-lobe design. 

"The handle size is larger and longer, especially on larger screwdrivers," says Rossi. "We found that people use screwdrivers in two ways. Either they use them in fine-touch applications where the thumb and forefinger do all the work, or in heavy applications where they wrap their hand around the whole handle and bear down on the dome of the screwdriver with the other hand. The tri-lobe design fits better in both uses." 

Perhaps one of the most interesting and easy-to-see innovations in tool design is the Armstrong Eliminator socket wrench set. Introduced two years ago, the tools address concerns that users have about socket wrenches, says Rossi. 

"Strength and the need to switch from a regular socket to a deep socket was a common complaint from contractors," he says. The Eliminator's through-hole design addresses these concerns. 

The wrench design allows all of the torque to be applied directly to the fastener, whereas with sockets, the force is concentrated above the fastener. That helps users break stubborn fasteners free easier. 

Box wrenches are also changing. Well-known for their ability to break stubborn fasteners free, they are a hassle to use when removing the fastener once it's loosened. To solve that, Armstrong offers a combination wrench that is a box wrench on one end and a hole-through socket wrench on the other end. 

"You can break a fastener free with the box wrench, then quickly remove it with the gearbox wrench on the other end," says Rossi.

This article originally appeared in the May/June '00 issue of Progressive Distributor. Copyright 2000.

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