- There is archaeological evidence of pocket knives being around staring in the 1st century. Excavations from sites in the Roman Empire found rudimentary designs of what we know know as the modern folding knife. The pocket knife did not become a popular tool, however, until the 16th century as sheath knives were commonly used up to that point. Pocket knives were never really used as a weapon, but became more popular as a compact tool used during travel. The Barlow pocket knife may be the most popular of all pocket knives. Invented by Luke Furnace of Stannington in 1760, the pocket knife was designed specifically for exportation and sale to the United States. Today, the "Barlow" is one of the most famous pocket knives for collectors. The last two centuries have seen the greatest innovations in the design and convenience of the pocket knife. Switch blades, which can be opened using only one hand and the invention of the locking mechanism that increases a pocket knives safety, are all technologies that occurred within the last 200 years.
- In general, pocket knives are identified by the ability to fit into an individuals pocket, but there are some folding knives that may be a bit larger than that general rule. A folding knife, on average, is between three and five inches, with a maximum of no more than six inches in length when folded. New pocket knife models, particularly those with multi-tool functions can be very thick, sometimes up to an inch in width. A new pocket knife tool recently on the market is the credit card pocket knife, which is the size width and length of credit card. While promising to perform all the basic tool functions of a pocket knife, the credit card knife is as thin as credit card.
- A simple, traditional pocket knife has a single blade that folds into the handle. Other pocket knives, like the German Army knife, has more than one blade. Pocket knives with more than one blade usually have an assortment of blade types like straight edge and serrated edge knives within there assortment of tools. Other features of pocket knives, particularly typical for the Leatherman and Swiss Army-brand pocket knife sets, include other common tools like corkscrews, screw drivers, scissors, pliers, nail files and bottle openers. Multi-tool pocket knife designs make up the majority of modern pocket knives.
- There are two main types of pocket knives available, with varied tools and capabilities within these two types. Slipjoint knives are a type of pocket knife in which the blade does not lock in place when it is open and therefore can be closed without pressing a button. Slipjoint knives open and close using a spring, so if the right amount of pressure is applied, the knife will close. Popular slipjoint knives are the Swiss Army Knife and Germany Army Knife. The other type of pocket knife is the locking knife, which has a hook attached to a spring. When the blade is opened, the spring pushes the lever into a notch on the handle, which locks the blade in place until a lever is pressed to release the hook. Leatherman is one of the more popular brand of knives that used a locking mechanism.
- There are some legal restrictions to consider when carry a pocket knife. Pocket knives cannot, for any reason, be carried onboard an airplane and many other forms of public transportation. Pocket knives are not allowed in schools, court houses or other federal buildings, and there may be restrictions on the carrying of a pocket knife in other public places as well. Switchblades, which are knives you can open using only one hand, are prohibited in almost all states unless you are an individual who only has the use of one hand. Many states have varying laws when it comes to the size and technology of a legal pocket knife, so be sure to check your local regulations before purchasing a pocket knife.
