How Does a Multi Tool Work? | Inside the Foldable Frame

For the full breakdown, see our best Cordless Multi Tool guide.

Whether you carry a Leatherman Wave+, a Victorinox Swiss Soldier’s Knife, or a budget pick, the mechanics behind how a multi-tool works are identical. Every model uses the same core system: folding handles that become pliers when opened, with each implement pivoting out and locking independently. Once you understand that geometry, you can operate almost any multi-tool.

The Core Mechanism: Handles That Become Pliers

The heart of a multi-tool is the hinged frame. When closed, the two handles sit side by side, concealing blades and drivers. Opened fully, those handles rotate 180 degrees and become the arms of pliers, with the jaw mechanism at the pivot point. Leatherman’s manual for the Wave+ describes this as the primary operation: grip the handles, open them completely, and the pliers are ready.

This design distinguishes a multi-tool from a Swiss Army knife. While both fold implements into a handle, the pliers are the anchor feature. Handles are thick enough for serious torque, and the jaw pivot is reinforced for cutting wire or gripping stubborn nuts. Once pliers are deployed, secondary implements come out of the handle halves, each pivoting on its own hinge and locking open to prevent closing on your fingers mid-task.

Deploying and Locking Individual Tools

Using a single implement follows a simple sequence across every brand. First, open the pliers fully, which unlocks internal tools in many designs. Second, pull the needed tool out until it clicks into the locked position. Third, confirm the lock is engaged before applying weight.

The lock is a safety feature, not a convenience. Leatherman’s Signal manual stresses never applying force until a tool is fully locked, whether using the saw on a branch or the knife on rope. A partially deployed blade can close suddenly with real force; the locking bar prevents that. To close, press the small release bar near the implement’s base, and the blade folds back. The pliers close last.

Not every tool locks on every model. Budget multi-tools often omit locks entirely—fine for light tasks, risky for heavy cutting. Check the manual for “locking” or “liner lock” if that matters to you.

What Each Tool Is Actually For

Different implements have distinct jobs; using the right one saves both tool and effort:

• Pliers and wire cutters – For gripping, bending, and cutting wire; replaceable cutters wear out and swap rather than dulling the jaw.
• Knife blades – The plain edge handles most cutting; serrated edge suits rope, strapping, and fibrous materials.
• Saws – For wood and branches only; a saw gums up and dulls quickly on metal or plastic.
• Files – For smoothing metal or wood; the coarse side removes material, the fine side finishes it.
• Screwdrivers and bit drivers – The bit driver takes standard bits; seat the bit fully before applying torque to avoid slipping and stripping screws.

Manuals also list can openers, bottle openers, awls, and wire strippers as standard. The Victorinox Swiss Soldier’s Knife, for example, folds a wood saw, Phillips screwdriver, can opener, and corkscrew into a frame measuring 111 mm closed and weighing 131 grams. That density is the entire point—one tool for every functional task.

Maintenance and Safety Basics

Keeping the tool working smoothly comes down to two habits. First, clean it after heavy use with fresh water or mild soap, then dry thoroughly before closing. Second, apply a small drop of light machine oil to pivot points; manuals note this improves stiffness and protects steel from rust after moisture exposure.

Safety is straightforward: confirm the lock before force, use blades on appropriate materials, and keep sharp edges away from your body. The Signal model even includes a ferrocerium rod and whistle for emergencies—a reminder that a multi-tool is often the only tool you have.

For everyday pocket carry, the classic manual design above is what you’ll reach for most.

On durability: the Leatherman Wave+ carries an 18-tool count and a 25-year warranty, a signal that the frame and locks outlast cheap alternatives. Such warranties are meaningful because the fold-and-lock system is simple enough to repair.