Patented in April 2003, Spyderco’s Compression Lock is the brainchild of the company’s founder Sal Glesser. Offering an amazing synthesis of strength, compactness, and ease of use, it is also one of the most underappreciated locking mechanisms in the knife industry.
When many people see a Compression Lock for the first time, they describe it as “a LinerLock on the back of the knife.” While the spring bar at the heart of the lock does resemble that of a Michael Walker-style LinerLock, the Compression Lock is very different. In a LinerLock, the tang of the blade features an angled or slightly concave “ramp” that faces the butt of the handle when the blade is open. The lock bar—a spring tab integral to one of the handles liners—is shaped so it is biased to move toward the center of the handle slot. When the blade is opened, it moves across the tang ramp and wedges against it, blocking the blade from closing.
In a Compression Lock, similar forces and mechanics are at work, but the geometry is very different. When the blade is open, the ramp on the tang of the blade faces upward, toward the top of the handle. It is also positioned directly below the stop pin that restricts the blade’s rotation to stop it in the open position. The lock bar—still integral to one of the handle’s liners—is positioned so when the blade is opened and it moves toward the center of the handle slot, it wedges between the bottom of the stop pin and the ramp on the blade tang.
When extreme pressure is applied to the back of the blade of a LinerLock, the lock ultimately fails when the lock bar bends or, more likely, when it slides off the ramp on the blade and allows it to close.
When pressure is applied to the back of the blade of a Compression Lock, rather than bending or moving the lock bar, the ramp on the blade must try to crush it along its vertical plane. Held in place by the stop pin at the top of the handle, the lock bar is “compressed” between that pin and the tang ramp. In order for the Compression Lock to fail, the stop pin must literally shear through the liners and out the top of the handle.
The Compression Lock is one of Spyderco’s strongest folding knife locks and can be found only on Spyderco products. Despite its extreme strength, it is also one of the safest and most user-friendly lock mechanisms—especially when closing a knife. By bracing your thumb against the left handle scale and pinching the lock release between your thumb and index finger, you can release the lock and swing the blade closed without ever placing your fingers in the path of the blade.
Simple, safe, reliable, and incredibly strong, the Compression Lock is yet another distinctive feature available exclusively from Spyderco.