A jack knife is a traditional two-blade pocket knife that comes in various shapes and sizes. It usually has a main blade that is a clip blade, and a second blade that is a pen blade.
This type of knife has a back-spring assembly that allows it to fold into its handle while closing. This hinging effect is what prompted the term jack knife.
Origin
A pocket knife called a jack knife has a mechanism that allows the blade to fold into its handle when not in use. It was invented in 1711 by French knife maker Jacque de Liege and became popular as a way to carry a knife without having to worry about the blade getting dirty or lost.
Interestingly, the term jack knife has also been used to describe a vehicle that folds inward in an accident. This happens when a truck or trailer swivels so that the cab and trailer are connected together at a 45-90 degree angle, like a jackknife.
The earliest reference to the term jackknife comes from Middle English jakke, “a mechanical device,” from the proper name Jack. It was then used to describe various appliances that do the work of common servants.
Function
The jack knife is a versatile tool that can be used for many purposes. It has multiple blades and can be folded up in a small package, making it easy to carry around.
A jack knife can be used to carve wooden fishing lures, letter openers and pot hooks. It can also be carved into wood sculptures.
Jack knives are a popular pocket knife, and they can be useful for camping and backpacking. They can be used to cut the ends of sticks for roasting hot dogs or marshmallows over a campfire, as well as to carve wooden eating utensils such as chopsticks.
The word jackknife can be traced back to 1711 when French knife maker Jacque de Liege invented a patented back-spring assembly that allowed the knife to fold inwards. The word eventually spread in English, and it has since evolved to refer to many things that fold inwards.
Styles
Pocket knives come in many different styles and have a long history. They are an iconic tool that evokes childhood nostalgia and a sense of adventure.
There are a wide range of blade types and sizes, so it’s important to choose the right type for your needs. A good rule of thumb is to pick a knife with a plain or partially serrated edge.
Partially serrated blades are ideal for cutting, sawing and slicing. However, they aren’t as sharp as plain edges.
There are also a variety of non-locking folding knives that use simple friction between the scales to hold the blade open once opened. These include the Japanese higonokami and the friction-folder.
Maintenance
Jack knives are clasp or folding knives with a blade that folds into the handle. Traditionally the blade is about five to 15 centimetres long.
There are many styles of jack knives and variations on the theme, so don’t be afraid to play around with different shapes and materials until you find the one that suits your needs best. The right model will make for a smooth, comfortable operation that won’t cramp your style.
If you’re in the market for a new jack knife, look for one made of quality steel that will hold up to heavy use. For example, if you’ll be using the tool in humid environments, consider choosing a stain-resistant alloy. You’ll also want a solid grip and a quality sheath to keep your jack in mint condition. And don’t forget to touch up the blade from time to time with a good sharpener. It’s not as hard as it sounds. The best ones will give you years of service.