Before any Leatherman multi-tool design is put into production, it must run a gauntlet of stress tests. Some engineers call the room housing these machines the Testing Lab. Tim Leatherman himself has dubbed it something more colorful: the Torture Chamber.

In the Torture Chamber, prototypes are twisted, poked, punched, prodded, bent, squeezed, and hammered. The goal? To simulate real-world conditions and see how new tools and their implements will hold up to the abuse.

To learn more about the Torture Chamber, the role it plays in product development, and where some of these specialized testing devices come from, we spoke with Peter Parker, Leatherman’s Product Design Engineering Lead. Here’s what he told us.

Hi, Peter. Thanks for taking the time to talk to us today. Can you introduce yourself and tell us a little bit about what you do here at Leatherman?

My title is “Lead Design Engineer”, which is just a normal Design Engineer that knows where all the bodies are buried...[laughs] Seriously though, at Leatherman the DE’s role is the protection of the user experience and product performance. That might come during design phase of NPD (New Product Development) or continuous improvement of existing products. For new products, we design products around user needs and create engineering specifications to measure performance.

It was interesting to see the date stamp (1996) on the File edge retention Machine. It looks like the Testing Lab can trace its origins back to the company's early days. Can you share what you know about its history and what role it plays today?

Leatherman has performance tested products since the beginning of the company. Although the tools are beautiful pocket “bling” and fun to fiddle with, that’s not the point of the tool. The saw needs to cut wood, the knife should hold an edge, and the pliers should cut baling wire. The lab is how we assess and measure those functions, by applying technical engineering requirements of the user experience.

If we recreated the 1996 era File Tester now, it would look a little different due to modern automation but would still be simulating the user’s experience of the material removal. Our customers aren’t filing off digital media in 2023; it’s still metal and wood (and maybe a torn fingernail).

It seems like testing in the lab falls into one of two broad buckets: testing the body of the tool for durability and then testing the individual implements for functionality. Is that a fair assessment?

Sure, but we realize the user isn’t going to separate body durability from implement function. If the handle snaps off, then the screwdriver isn’t going to be as useful… But yes, we can separate some of the functions into a unique part which is independent of the architecture that holds it. A Leatherman saw should cut a wood dowel at the same rate whether it’s installed in a 4.5” Surge® or a more modest Sidekick®.

Talk to us about some of the testing devices and how they are engineered and/or sourced. Is "the Octopus" or the Strap Cutter something you can buy off the shelf or are we designing and building them from scratch?

The lab contains a range of test equipment, some that we purchase complete and others that are custom to Leatherman. Knife processing is measured via “edge retention” on an industry standard CATRA device. We also have the Universal Test Machine that is an instrumented platform that pushes and pulls whatever we put in its path.

The Octopus is our nickname for a set of linear slides that we perform all our cycle testing. Some of the UTM and Octopus fixturing is beautifully thought out and others are, well, more zip-tie and bubble gum MacGyvered than calibrated science. New features and functions require following hunches down quick and dirty test routes.

With a multi-tool like ARc that's been under development for years, how early is the Testing Lab involved?

The Design Engineering team begins using the lab when the next product is just a sketch on a napkin. Prototypes’ test results tell us if we are headed in the right direction before we waste a lot of resources on a dead-end design.

Let's say a new prototype is brought to you for testing. Is there a checklist you follow or is the process more ad hoc and does it vary according to the needs of that particular tool? In other words, walk us through the process of how a tool gets tested.

This question is assuming a scenario that’s a little off. Each engineer is responsible for their own design, prototypes, and to determine whatever testing is required. We do have a lab technician (Anthony) who may physically perform the test. Often the engineer and Lab Tech will work together to create and qualify a new test. Test requirements are often common between different products (i.e., handle grip strength, can opening, prying, nail cutting, etc.) and those tests can be modified and repeated.

So, you've gotten test results. What happens next?

The lab is a way to measure the performance of a given function. Initially on a new function, there is a lot of feedback required from the user demographic to determine what they value and what performance meets their needs. Later, once that’s been established, we use test results to measure the design and the manufacturing processes of the product. These later tests are either an audit of quality or perhaps troubleshooting or improving a production process.

Can you think of an instance where testing helped the product evolve or deliver new benefits that maybe were unexpected?

During the initial design of the FREE series pliers (P2, P4), we needed a mechanism that could provide the handle deploy detent with high force over a short distance. Steel features make lousy springs for this, so we started working with urethane cylinders tucked into the plier's ear. Testing showed they solved the handle detent torque and positive sounding “click” open, but also cycle testing on the Octopus lasted forever. I’d share test results with you, but we literally could not get a failure after a million cycles. Stress corrosion cracking also kills steel springs, but not urethane, so it’s almost pointless to test rubber in a salt fog environment (we did anyway).

Do you have a favorite torture device?

The most used implement on my daily carry ARC is the Pry Bar. Yes, the design isn’t anything fancy; it’s just a thick screwdriver. But lab testing has shown this tool can take normal user “abuse”. This implement eliminates the cringe and shame of bending or snapping-off another random implement. This makes me happy (and maybe our Warranty dept. too?).

thanks, peter!

A huge thank you to Peter for taking the time to talk to us and inviting us into the lab.

ready to read more?

Interested in more insights from Leatherman’s engineers? Watch Leatherman CEO Ben Rivera talk about the History of the Wave, and learn how this bestselling multi-tool came to life. Or take a peek inside our factory when Essential Craftsman stopped by for a tour.