Lock Types

Generally, a locking system on a folding knife is designed to keep the blade locked open until the user releases it—so there’s no danger of the blade folding back. In addition, most ZT knives have a detent to bias the knife toward the closed position for safe carrying. Learn about ZT locking systems and how to use them, as well as read more about detent below.

Frame Lock

In a frame lock knife, the knife handle—its “frame”—consists of two plates of material on either side of the blade. When the knife is opened, the metal side of the frame, the lockbar, butts up against the backend of the blade (the tang) and prevents the blade from closing.

To unlock a frame lock:

1. Hold the knife handle in one hand.
2. Turn the knife so that you can see the interior of the handle.
3. On the left side of the handle, you will see that one side of the handle (also called the “frame”) is positioned behind the blade. This is the lock.
4. With your thumb, press the lock to the left so that it is no longer blocking the blade.
5. With your other hand, hold the back of the blade (away from the edge) and begin to guide the blade back into the handle.
6. Move your thumb out of the way as you finish guiding the blade back into the handle.

Inset Liner Lock

The inset liner lock is a variation on the liner lock that enables ZT to provide the security of a locking liner in a knife that’s slimmer and lighter. We inset a sturdy steel plate on the inside of the knife’s handle. This partial liner is riveted into place in a machined cutout on the interior of the handle. We don’t need a complete steel liner on both sides of the handle, so  the knife can be lighter, thinner, and easier to carry.

To unlock an inset liner lock:

1. Hold the knife handle in one hand.
2. Turn the knife so that you can see the interior of the handle.
3. On the left side of the handle you will see an inset piece of steel is positioned behind the blade. This is the lock.
4. With your thumb, press the lock to the left so that it is no longer blocking the blade.
5. With your other hand, hold the back of the blade (away from the edge) and begin to guide the blade back into the handle.
6. Move your thumb out of the way as you finish guiding the blade back into the handle.

Liner Lock

The liner lock is the most common of today’s blade-locking systems. In knives with locking liners, the handle consists of two metal plates (the “liner”) on either side of the blade. Handle scales, which can be made from a variety of materials, such as G10, cover the plates.

To unlock a liner lock:

1. Hold the knife handle in one hand.
2. Turn the knife so that you can see the interior of the handle.
3. On the left side of the handle, you will see the steel liner is positioned behind the blade. This is the lock.
4. With your thumb, press the lock to the left so that it is no longer blocking the blade.
5. With your other hand, hold the back of the blade (away from the edge) and begin to guide the blade back into the handle.
6. Move your thumb out of the way as you finish guiding the blade back into the handle.

Sub-Frame Lock

The ZT Sub-Frame Lock is our patented variation on the traditional frame lock that lets us make a slimmer knife while providing a strong, secure lock. In this case, a piece of the lighter weight frame, often carbon fiber, is machined out and a piece of steel is riveted into its place. This piece of steel acts just like a standard frame lock. When the blade is open, it moves into position behind the blade tang, locking it open.

To unlock a Sub-Frame Lock:

1. Hold the knife handle in one hand.
2. Turn the knife so that you can see the interior of the handle.
3. On the left side of the handle you will see part of the frame is positioned behind the blade. This is the lock.
4. With your thumb, press the lock to the left so that it is no longer blocking the blade.
5. With your other hand, hold the back of the blade (away from the edge) and begin to guide the blade back into the handle.
6. Move your thumb out of the way as you finish guiding the blade back into the handle.
7. The Sub-Frame Lock is covered under US Patent 9,120,234.

Slipjoint

A slipjoint knife is a knife with no lock. However, these knives use other mechanisms to ensure safe use.

ZT slipjoints use a ball detent. There is a small indentation on the blade into which a tiny steel ball on the frame or liner lock fits as the knife is opened or closed. This provides friction and a light "stop" that biases the knife to the closed position and ensures controlled open and close.

To close a slipjoint:

1. Hold the knife handle in one hand.
2. Hold the back of the blade (away from the edge) with the other hand.
3. Slowly guide the blade back into the handle, making sure to keep your fingers out of the path of the blade as you close it.