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Punch (metalworking)
A punch is a tool used to indent or create a hole through a hard surface. They usually consist of a hard metal rod with a narrow tip at one end and a broad flat "butt" at the other. When used, the narrower end is pointed against a target surface and the broad end is then struck with a hammer or mallet, causing the blunt force of the blow to be transmitted down the rod body and focused more sharply onto a small area. Typically, woodworkers use a ball-peen hammer to strike a punch. Use Punches are used to drive fasteners such as nails and dowels, making a hole, or forming an indentation/impression of the tip on a workpiece. Decorative punches may also be used to create a pattern or even form an image. Pin Metal pins and similar connectors are driven in or out of holes using a pin punch. For removal, first use a starter punch to loosen the pin, then use a pin punch to finish. Center A ''center punch'' is used to mark the center of a point. It is usually used to ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automatic Centre Punch
An automatic center punch is a hand tool used to produce a dimple in a workpiece (for example, a piece of metal). It performs the same function as an ordinary center punch but without the need for a hammer. When pressed against the workpiece, it stores energy in a spring, eventually releasing it as an impulse that drives the punch, producing the dimple. The impulse provided to the point of the punch is quite repeatable, allowing for uniform impressions to be made. History The patent history of automatic punches indicates two principal goals for the development of the tool: repeatability of impact, and convenience of operation. Other desirable properties include low recoil when triggered, ease of adjustment, and reliability. A number of designs for automatic center punches have been developed since the late 19th century as improvements over punches requiring the use of a striking tool. The earliest types were not fully automatic, using a captive weight lifted by the user or a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bookbinding
Bookbinding is the process of physically assembling a book of codex format from an ordered stack of ''signatures'', sheets of paper folded together into sections that are bound, along one edge, with a thick needle and strong thread. Cheaper, but less permanent, methods for binding books include loose-leaf rings, individual screw-posts (binding posts), twin loop spine coils, plastic spiral coils, and plastic spine combs. For protection, the bound stack of signatures is wrapped in a flexible cover or is attached to stiffened boards. Finally, an attractive cover is placed onto the boards, which includes the publisher's information, and artistic decorations. The trade of binding books is in two parts; (i) stationery binding (vellum binding) for books intended for handwritten entries, such as accounting ledgers, business journals, blank-page books, and guest logbooks, and notebooks, manifold books, day books, diaries, and portfolios. (ii) letterpress printing and binding deals wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goldsmith
A goldsmith is a metalworker who specializes in working with gold and other precious metals. Nowadays they mainly specialize in jewelry-making but historically, goldsmiths have also made silverware, platters, goblets, decorative and serviceable utensils, and ceremonial or religious items. Goldsmiths must be skilled in forming metal through filing, soldering, sawing, forging, casting, and polishing. The trade has very often included jewelry-making skills, as well as the very similar skills of the silversmith. Traditionally, these skills had been passed along through apprenticeships; more recently jewelry arts schools, specializing in teaching goldsmithing and a multitude of skills falling under the jewelry arts umbrella, are available. Many universities and junior colleges also offer goldsmithing, silversmithing, and metal arts fabrication as a part of their fine arts curriculum. Gold Compared to other metals, gold is malleable, ductile, rare, and it is the only soli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leather
Leather is a strong, flexible and durable material obtained from the tanning, or chemical treatment, of animal skins and hides to prevent decay. The most common leathers come from cattle, sheep, goats, equine animals, buffalo, pigs and hogs, and aquatic animals such as seals and alligators. Leather can be used to make a variety of items, including clothing, footwear, handbags, furniture, tools and sports equipment, and lasts for decades. Leather making has been practiced for more than 7,000 years and the leading producers of leather today are China and India. Animal rights groups claim that modern commercial leather making and the consumption of its products is unethically killing animals. According to the life-cycle assessment (LCA) report for the United Nations Industrial Development Organization, 99% of the raw hides and skins used in the production of leather derive from animals raised for meat and/or dairy production. Critics of tanneries claim that they engage in u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spring Pin
A spring pin (also called tension pin or roll pin) is a mechanical fastener that secures the position of two or more parts of a machine relative to each other. Spring pins have a body diameter which is larger than the hole diameter, and a chamfer on either one or both ends to facilitate starting the pin into the hole. The spring action of the pin allows it to compress as it assumes the diameter of the hole. The force exerted by the pin against the hole wall retains it in the hole, therefore a spring pin is considered a self retaining fastener. Spring pins may be used to retain a shaft as a journal in a plain bearing A plain bearing, or more commonly sliding contact bearing and slide bearing (in railroading sometimes called a solid bearing, journal bearing, or friction bearing), is the simplest type of bearing, comprising just a bearing surface and no roll ..., as a type of key to fasten one shaft to another, or to precisely fasten flat faces of mating parts together throu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roll Pin Punches
Roll or Rolls may refer to: Movement about the longitudinal axis * Roll angle (or roll rotation), one of the 3 angular degrees of freedom of any stiff body (for example a vehicle), describing motion about the longitudinal axis ** Roll (aviation), one of the aircraft principal axes of rotation of an aircraft (angle of tilt to the left or right measured from the longitudinal axis) ** Roll (ship motion), one of the ship motions' principal axes of rotation of a ship (angle of tilt to the port or starboard measured from the longitudinal axis) * Rolling ''manoeuvre'', a manoeuvre of any stiff body (for example a vehicle) around its roll axis: ** Roll, an aerobatic maneuver with an airplane, usually referring to an aileron roll, but sometimes instead a barrel roll, rudder roll or slow roll ** Kayak roll, a maneuver used to right a capsized kayak ** Roll program, an aerodynamic maneuver performed in a rocket launch * Roll rate (or roll velocity), the angular speed at which an aircraft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rivet
A rivet is a permanent mechanical fastener. Before being installed, a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite to the head is called the ''tail''. On installation, the rivet is placed in a punched or drilled hole, and the tail is ''upset'', or ''bucked'' (i.e., deformed), so that it expands to about 1.5 times the original shaft diameter, holding the rivet in place. In other words, the pounding or pulling creates a new "head" on the tail end by smashing the "tail" material flatter, resulting in a rivet that is roughly a dumbbell shape. To distinguish between the two ends of the rivet, the original head is called the ''factory head'' and the deformed end is called the ''shop head'' or buck-tail. Because there is effectively a head on each end of an installed rivet, it can support tension loads. However, it is much more capable of supporting shear loads (loads perpendicular to the axis of the shaft). Fastenings used in traditional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drift Punch
In metalworking, a drift pin, drift pin punch, simply drift, is the name for a tool used for localizing a hammer blow. A drift is smaller in diameter than the hammer face, thus concentrating the force into a smaller area. A drift is also used where the surrounding surfaces need to be protected from the hammer blow. A drift is not used as a punch in the traditional sense of the term. Unlike most punches, force should never be applied to the tip of drift pin. Drifts are constructed from wood, light alloys, copper, or steel which are usually rods cut to size as for the job. Drifts can be used to remove dents from inaccessible places, for striking pins and keys out. Some drift pins are constructed with a taper, with the hammer acting on the large end of the taper. The tapered drift pin is used to align the two bolt holes in two separate components that are designed to mate. First the two components are maneuvered until the holes in each are in semi-alignment, such that the narrow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taps And Dies
Taps and dies are tools used to create screw threads, which is called threading. Many are cutting tools; others are forming tools. A tap is used to cut or form the female portion of the mating pair (e.g. a nut). A die is used to cut or form the male portion of the mating pair (e.g. a bolt). The process of cutting or forming threads using a tap is called ''tapping'', whereas the process using a die is called ''threading''. Both tools can be used to clean up a thread, which is called ''chasing''. However, using an ordinary tap or die to clean threads generally removes some material, which results in looser, weaker threads. Because of this, machinists generally clean threads with special taps and dies—called ''chasers''—made for that purpose. Chasers are made of softer materials and don't cut new threads. However they still fit tighter than actual fasteners, and are fluted like regular taps and dies so debris can escape. Car mechanics, for example, use chasers on spark plug th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Index Set
In mathematics, an index set is a set whose members label (or index) members of another set. For instance, if the elements of a set may be ''indexed'' or ''labeled'' by means of the elements of a set , then is an index set. The indexing consists of a surjective function from onto , and the indexed collection is typically called an '' (indexed) family'', often written as . Examples *An enumeration of a set gives an index set J \sub \N, where is the particular enumeration of . *Any countably infinite set can be (injectively) indexed by the set of natural numbers \N. *For r \in \R, the indicator function on is the function \mathbf_r\colon \R \to \ given by \mathbf_r (x) := \begin 0, & \mbox x \ne r \\ 1, & \mbox x = r. \end The set of all such indicator functions, \_ , is an uncountable set indexed by \mathbb. Other uses In computational complexity theory and cryptography Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''grap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Punch (transfer)
Punch commonly refers to: * Punch (combat), a strike made using the hand closed into a fist * Punch (drink), a wide assortment of drinks, non-alcoholic or alcoholic, generally containing fruit or fruit juice Punch may also refer to: Places * Punch, U.S. Virgin Islands * Poonch (other), often spelt as Punch, several places in India and Pakistan People * Punch (surname), a list of people with the name * Punch (nickname), a list of people with the nickname * Punch Masenamela (born 1986), South African footballer * Punch (rapper), 21st century American rapper Terrence Louis Henderson Jr. * Punch (singer), South Korean singer Bae Jin-young (born 1993) Arts, entertainment and media Fictional entities * Mr. Punch (also known as Pulcinella or Pulcinello), the principal puppet character in the traditional '' Punch and Judy'' puppet show * Mr. Punch, the masthead image and nominal editor of ''Punch'', largely borrowed from the puppet show * Mr. Punch, a fictional character ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
