Quarter (United States coin) in the context of "Threaded fastener"

A fastener (US English) or fastening (UK English) is a hardware device that mechanically joins or affixes two or more objects together. In general, fasteners are used to create non-permanent joints; that is, joints that can be removed or dismantled without damaging the joining components. Steel fasteners are usually made of stainless steel, carbon steel, or alloy steel.

Other methods of joining materials, some of which may create permanent joints, include: crimping, welding, soldering, brazing, taping, gluing, cement, or the use of other adhesives. Force may also be used, such as with magnets, vacuum (like suction cups), or even friction (like sticky pads). Some types of woodworking joints make use of separate internal reinforcements, such as dowels or biscuits, which in a sense can be considered fasteners within the scope of the joint system, although on their own they are not general-purpose fasteners.

A screw is an externally helical threaded fastener capable of being tightened or released by a twisting force (torque) to the head. The most common use of screws is to hold objects together and there are many forms for a variety of materials. Screws might be inserted into holes in assembled parts or a screw may form its own thread. The difference between a screw and a bolt is that the latter is designed to be tightened or released by torquing a nut.

The screw head on one end has a slot or other feature that commonly requires a tool to transfer the twisting force. Common tools for driving screws include screwdrivers, spanners, wrenches, coins and hex keys. The head is usually larger than the body, which provides a bearing surface and keeps the screw from being driven deeper than its length; an exception being the set screw (aka grub screw). The cylindrical portion of the screw from the underside of the head to the tip is called the shank; it may be fully or partially threaded with the distance between each thread called the pitch.

The United States Bicentennial coinage is a set of circulating commemorative coins, consisting of a quarter, half dollar and dollar struck by the United States Mint in 1975 and 1976. Regardless of when struck, each coin bears the double date 1776–1976 on the normal obverses for the Washington quarter, Kennedy half dollar and Eisenhower dollar. No coins dated 1975 of any of the three denominations were minted.

Given past abuses in the system, the Mint advocated against the issuance of commemorative coins starting in the 1950s. Beginning in 1971, members of Congress introduced bills to authorize coins to honor the United States Bicentennial, which would occur in 1976. The Mint, through its director, Mary Brooks, initially opposed such proposals, but later supported them, and Congress passed legislation requiring the temporary redesign of the reverse of the quarter, half dollar and dollar.

The half dollar, sometimes referred to as the half for short or 50-cent piece, is a United States coin worth 50 cents, or one half of a dollar. In both size and weight, it is the largest circulating coin currently minted in the United States, being 1.205 inches (30.61 millimeters) in diameter and 0.085 in (2.16 mm) in thickness, and is twice the weight of the quarter. The coin's design has undergone a number of changes throughout its history. Since 1964, the half dollar depicts the profile of President John F. Kennedy on the obverse and the seal of the president of the United States on the reverse.

Although seldom used today, half-dollar coins were once common in circulation and saw regular use alongside other denominations of US coinage, but have become uncommon in general circulation for several reasons. Half-dollars were produced in fairly large quantities until the year 2002, when the U.S. Mint reduced production of the coin and ceased minting them for regular circulation. As a result of its decreasing usage, many pre-2002 half dollars remain in Federal Reserve vaults, prompting the change in production. Presently, collector half dollars can be ordered directly from the U.S. Mint, and circulated half dollars minted from 1971 to 2001 are generally available at most American banks and credit unions. Beginning in 2021, half dollars were again produced for general circulation.

Coin edges are the parts of a coin's surface between the faces; they may be plain (smooth) or patterned, or a combination of both. They can also include lettering.

Reeded edges are often referred to as "ridged" or "grooved" (US usage), or "milled" (UK usage). Some coins, such as United States quarters and dimes, have reeded edges. Reeding of edges was introduced to prevent coin clipping and counterfeiting.

A thaler, or taler (/ˈtɑːlər/ TAH-lər; German: Taler [ˈtaːlɐ], previously spelled Thaler), is one of the large silver coins minted in the states and territories of the Holy Roman Empire and the Habsburg monarchy during the Early Modern period. A thaler size silver coin has a diameter of about 40 mm (1+1⁄2 in) and a weight of about 25 to 30 grams (roughly 1 ounce). The word is shortened from Joachimsthaler, the original thaler coin minted in Joachimsthal, Bohemia, from 1520.

While the first standard coin of the Holy Roman Empire was the Guldengroschen of 1524, its longest-lived coin was the Reichsthaler, which contained 1⁄9 Cologne Mark of fine silver (or 25.984 g), and which was issued in various versions from 1566 to 1875. From the 17th century a lesser-valued North German thaler currency unit emerged, which by the 19th century became par with the Vereinsthaler.