The Zero Tolerance 0550 is an extremely heavy-duty folding pocket knife made from S35VN stainless steel and textured G-10. It has been described as a beast of a knife, and it’s probably more suited to carving through the side of a wrecked car than slicing peaches. Due to its large size, you may want to keep it concealed when you’re near other people — at the grocery store, for example — but the large grip and textured G-10 make it a pleasure to hold. Some owners have reported that opening the ZT 0550 is somewhat difficult at first, but this stiffness is part of the design and wears off after a week or so of opening it. In other words, you probably won’t be able to open it one-handed until you loosen the hinge a little with practice.
When you receive the ZT 0550, it’s extremely sharp, and the edge stays sharp after a couple of weeks of heavy use. This excellent ability to retain an edge is due to the new steel material used to construct the blade; S35VN is a slightly firmer steel than S30V, the material used to make previous Zero Tolerance knives, and the newer material is less prone to chips or dulling. The new material raises the price a little, but the ZT 0550 is still a lot less expensive than knives that aren’t as sturdy and well-made. It was designed by Rick Hinderer, the famous knife designer known for his long-lasting, pricey blades, but the ZT 0550 is less expensive than other Rick Hinderer knives.
The S35VN steel has a beautiful stone-washed finish with heavy-duty jimping where the thumb rests while making cuts. The blade pivots on two large-size bronze washers, which allow it to flick out smoothly without any play in the blade at all. Very few owners have commented on any play in the blade, and several people have said that they were able to open the knife one-handed on the first day they owned it.
This knife is basically a survival-type knife that you could use for anything from fending off zombies to cutting up cardboard boxes, but it comes with a deep-carry clip so that you can easily conceal it in a pocket. The clip can be adjusted to hold the knife for left- or right-handed owners or to hold it with the blade pointed up or down. When the knife is clipped in your pocket, hardly any of the handle is visible at all.
The clip is located on the titanium alloy side of the handle rather than the textured G-10 side. The dual-material handle is attractive to the eye but also extremely functional, as it was designed to be. Rather than ordinary G-10, the ZT 0550 uses a very grippy texture for the black side of the handle and high-quality titanium for the metal side. The two halves are fastened together using torx screws and steel spacers, and the lock bar falls smoothly into place when the blade is opened, like on a Chris Reeve knife. The scaled milling on the G-10 side of the handle looks and feels different when you hold it than it does in pictures. A few owners who didn’t like the texture ended up replacing the handle with an aftermarket G-10 or titanium knife handle, but almost everyone who has receive the knife has responded positively to the scaled G-10.
The stand-off pillars that hold the two sides of the handle apart give you a perfect place to tie a lanyard, and they make cleaning the knife much easier. Additionally, the open space between the two halves makes the knife lighter than it would be with a solid piece of G-10 for the handle. It’s not an assisted-opening knife, but the bronze-phosphor washers give the blade a very smooth action. There are no springs in the handle; the knife must be opened by flicking the steel bar with your thumb or by pulling the knife open with both hands. The initial stiffness of the blade is simply a trade-off due to the knife’s firmness and lack of play. All in all, the ZT 0550 is a sturdily constructed knife that will last a lifetime if you take care of it.