Opening a folding knife may seem like a fairly straightforward topic. You take the knife out and you open the blade. The reality is that this is one of the most important features depending on the scenario in which the knife is used. Foremost if the pocket knife you carry is for self-defense, then you want to be assured that when the time comes you can quickly and safely have the knife at the ready. Here we would like to discuss some of the more common but innovative ways to deploy your folding knife and their tactical advantages.
This is the oldest trick in the knife deploy book. The nail mark is the small divot located on the blade near the spine. This miniscule indentation offered just enough purchase for users to pinch and open the blade. This method is a step forward from just grabbing the blade and simple enough to add to any folder, but has been overshadowed by improved techniques.
Thumb stud or thumb hole
The thumb stud has been the next in line in the evolution of knife opening. A small, usually rounded, metal stud located on the blade closest to the pivot. This addition gave the thumb something to push against making blade deployment much easier. It also removed the need to use two hands to hold the knife while trying to open, unlike the nail mark. Closely related is the thumb hole. Being a full cutout of the blade this also allowed for the thumb to bush against the steel but also added the benefit of being effective in either hand.
Assisted open knives have started to dominate the folder market in that they deploy fast, but do not encounter the restrictions that are associated with automatic knives. In assisted knives, a small spring is placed in the blade that helps swing the blade into the fully open position. However, this mechanism only engages after the blade has been opened a sufficient amount. To help facilitate this deployment, many assisted knives have a small "flipper" that protrudes from the closed blade to help ease the opening along.
The most popular and often romanticized method of deploy is found in automatic knives. These knives have a spring that fully deploys the knife at the push of a button. Incredibly efficient and easy to use, these knives have unfortunately been the subject of many rules and regulations.
Pocket deploy/ snag system
The snag system involves having a small protrusion of metal on folding knives, that when properly caught by the pocket seam will fully open a knife blade while the knife is being pulled out. While this method can be very quick and has little risk of activating accidentally, it does take some practice to be able to consistently use.