A knife (pl.: knives; from Old Norse knifr 'knife, dirk'[1]) is a tool or weapon with a cutting edge or blade, usually attached to a handle or hilt. One of the earliest tools used by humanity, knives appeared at least 2.5 million years ago, as evidenced by the Oldowan tools.[2][3] Originally made of wood, bone, and stone (such as flint and obsidian), over the centuries, in step with improvements in both metallurgy and manufacturing, knife blades have been made from copper, bronze, iron, steel, ceramic, and titanium. Most modern knives have either fixed or folding blades; blade patterns and styles vary by maker and country of origin.

Knives can serve various purposes. Hunters use a hunting knife, soldiers use the combat knife, scouts, campers, and hikers carry a pocketknife; there are kitchen knives for preparing foods (the chef's knife, the paring knife, bread knife, cleaver), table knife (butter knives and steak knives), weapons (daggers or switchblades), knives for throwing or juggling, and knives for religious ceremony or display (the kirpan).[4]

Free Download Knife Rar

tag_hash_106 🔥 https://bytlly.com/2yjWvj 🔥

The handle, used to grip and manipulate the blade safely, may include a tang, a portion of the blade that extends into the handle. Knives are made with partial tangs (extending part way into the handle, known as "stick tangs") or full tangs (extending the full length of the handle, often visible on top and bottom). There is also the enterado construction method present in antique knives from Brazil, such as the Sorocaban Knife, which consists in riveting a repurposed blade to the ricasso of a bladeless handle. The handle may include a bolster, a piece of heavy material (usually metal) situated at the front or rear of the handle. The bolster, as its name suggests, is used to mechanically strengthen the knife.

A folding knife connects the blade to the handle through a pivot, allowing the blade to fold into the handle. To prevent injury to the knife user through the blade accidentally closing on the user's hand, folding knives typically have a locking mechanism. Different locking mechanisms are favored by various individuals for reasons such as perceived strength (lock safety), legality, and ease of use.Popular locking mechanisms include:

Another prominent feature of many folding knives is the opening mechanism. Traditional pocket knives and Swiss Army knives commonly employ the nail nick, while modern folding knives more often use a stud, hole, disk, or flipper located on the blade, all of which have the benefit of allowing the user to open the knife with one hand.

Automatic or switchblade knives open using the stored energy from a spring that is released when the user presses a button or lever or other actuator built into the handle of the knife. Automatic knives are severely restricted by law in the UK and most American states.[18]

In the lock back, as in many folding knives, a stop pin acting on the top (or behind) the blade prevents it from rotating clockwise. A hook on the tang of the blade engages with a hook on the rocker bar which prevents the blade from rotating counter-clockwise. The rocker bar is held in position by a torsion bar. To release the knife the rocker bar is pushed downwards as indicated and pivots around the rocker pin, lifting the hook and freeing the blade.

When negative pressure (pushing down on the spine) is applied to the blade all the stress is transferred from the hook on the blade's tang to the hook on the rocker bar and thence to the small rocker pin. Excessive stress can shear one or both of these hooks rendering the knife effectively useless. Knife company Cold Steel uses a variant of the lock back called the Tri-Ad Lock which introduces a pin in front of the rocker bar to relieve stress on the rocker pin, has an elongated hole around the rocker pin to allow the mechanism to wear over time without losing strength and angles the hooks so that the faces no longer meet vertically.

The bolt in the bolt lock is a rectangle of metal that is constrained to slide only back and forward. When the knife is open a spring biases the bolt to the forward position where it rests above the tang of the blade preventing the blade from closing. Small knobs extend through the handle of the knife on both sides allowing the user to slide the bolt backward freeing the knife to close. The Axis Lock used by knife maker Benchmade is functionally identical to the bolt lock except that it uses a cylinder rather than a rectangle to trap the blade.[13] The Arc Lock by knife maker SOG is similar to the Axis Lock except the cylinder follows a curved path rather than a straight path.[14]

In the liner lock, an L-shaped split in the liner allows part of the liner to move sideways from its resting position against the handle to the centre of the knife where it rests against the flat end of the tang. To disengage, this leaf spring is pushed so it again rests flush against the handle allowing the knife to rotate.[8] A frame lock is functionally identical but instead of using a thin liner inside the handle material uses a thicker piece of metal as the handle and the same split in it allows a section of the frame to press against the tang.[8]

A sliding knife is a knife that can be opened by sliding the knife blade out the front of the handle. One method of opening is where the blade exits out the front of the handle point-first and then is locked into place (an example of this is the gravity knife). Another form is an OTF (out-the-front) switchblade, which only requires the push of a button or spring to cause the blade to slide out of the handle and lock into place. To retract the blade back into the handle, a release lever or button, usually the same control as to open, is pressed. A very common form of sliding knife is the sliding utility knife (commonly known as a stanley knife or boxcutter).

More exotic materials usually only seen on art or ceremonial knives include: Stone, bone, mammoth tooth, mammoth ivory, oosik (walrus penis bone), walrus tusk, antler (often called stag in a knife context), sheep horn, buffalo horn, teeth, and mop (mother of pearl or "pearl"). Many materials have been employed in knife handles.

Handles may be adapted to accommodate the needs of people with disabilities. For example, knife handles may be made thicker or with more cushioning for people with arthritis in their hands. A non-slip handle accommodates people with palmar hyperhidrosis.

The knife plays a significant role in some cultures through ritual and superstition, as the knife was an essential tool for survival since early man.[3] Knife symbols can be found in various cultures to symbolize all stages of life; for example, a knife placed under the bed while giving birth is said to ease the pain, or, stuck into the headboard of a cradle, to protect the baby;[citation needed] knives were included in some Anglo-Saxon burial rites, so the dead would not be defenseless in the next world.[21][22] The knife plays an important role in some initiation rites, and many cultures perform rituals with a variety of knives, including the ceremonial sacrifices of animals.[23] Samurai warriors, as part of bushido, could perform ritual suicide, or seppuku, with a tant, a common Japanese knife.[24] An athame, a ceremonial knife, is used in Wicca and derived forms of neopagan witchcraft.[25][26]

In Greece, a black-handled knife placed under the pillow is used to keep away nightmares.[citation needed] As early as 1646 reference is made to a superstition of laying a knife across another piece of cutlery being a sign of witchcraft.[27] A common belief is that if a knife is given as a gift, the relationship of the giver and recipient will be severed. Something such as a small coin, dove or a valuable item is exchanged for the gift, rendering "payment."[citation needed]

Some types of knives are restricted by law, and carrying of knives may be regulated, because they are often used in crime, although restrictions vary greatly by jurisdiction and type of knife. For example, some laws prohibit carrying knives in public while other laws prohibit possession of certain knives, such as switchblades.[28][29]

The experience at knife is always top notch. I ask for the bar seating every time as you have a perfect view of the chefs preparing the beautifully aged meats...They are just as special and delicious. Service is always great here. Price range will go for about 150/person on average if you're ordering any of their special steaks.

Another important caveat before we get to the ratings are that these are for the steel only. This does not predict which knife will cut longer or be more resistant to chipping. The reason is because sharpening and edge geometry will also greatly control properties. For example, see the chart below for how much edge retention can change with edge geometry for a single steel (in this case 154CM and CPM-154). Using 10 dps sharpening (20 degrees inclusive on the chart) leads to about 5x the edge retention of 25 dps.

You can read about my CATRA edge retention testing in this article. Each steel was tested with a knife that was produced just for the test, and then sharpened the same way for each test (15 dps 400 grit CBN sharpening). A few steels have been added since such as MagnaCut and M398. I also added a few more steels in this study. The studies confirmed that the primary controlling factors are hardness of the steel, volume of carbides, and hardness of the carbides. The highest edge retention steel was Rex 121 which was at 70 Rc in combination with lots of high hardness vanadium carbides. We can predict edge retention of a steel within a relatively narrow band based on hardness and carbide volume. We should be suspicious of anyone who is claiming very high edge retention with a steel at low hardness and a small amount of carbide. The chart below has dotted lines which indicate the average effect of hardness for any given steel. So you can estimate how much a change in hardness would affect edge retention by following the slope of those lines. 0852c4b9a8

cfa level 1 books pdf free download

fl studio 9 free download with crack

free download 100 love bengali video songs