A more expensive treatment for brass pins, primarily for decorative purposes, is gilting. For brass safety pins, nickel coatings are used, as they resist some chemicals and remain attractive for a long period. One of these methods is to coat the pin with the chemical chromate, particularly on spring-steel safety pins. If the pin is to be subjected to damp environments or to a piece of cloth for a long period of time, other treatments are used to prevent stains from corrosion of the steel. The most commonįinish on spring-steel pins is chrome, followed by a final wax coat. Other raw materials include a variety of coatings and platings. However, for some safety pin applications, a type of low-carbon stainless steel -ferritic, which costs less than stainless steel -is used. With a mirror-like finish, stainless steel is used when corrosion, temperature, and strength are considerations. More expensive than brass, stainless steel is an alloy that includes chromium and nickel (manganese is sometimes used instead of nickel). The strength of brass is adequate for most safety pin applications. It is nonmagnetic and easily worked into shape. More expensive than spring steel, this metal will polish up to a high luster. By varying the proportion of carbon added to iron, spring steel can have high tensile strength and resiliency that allows it to flex and return to its original shape.īrass is an alloy of approximately two-thirds copper and one-third zinc. Most fasteners without critical strength requirements are made from spring steel, an alloy of iron that has a high carbon content (more than 0.5%). The most common metals used in safety pins are spring steel, brass, and stainless steel. Today the largest user of safety pins is the retail sewing notions market, while the largest commercial user is the laundry and cleaning industry. In the 15th century, pins were manufactured from drawn wire, a process that still exists in the manufacture of modern safety pins. These were fashioned out of skewers of wood for common people, or out of bone, ivory, silver, gold, or brass for those of wealth and high position. In the Middle Ages, the design reverted to one resembling a straight pin. The fibula became widely used throughout the ancient world as the Roman Empire expanded. An Iranian pin from this period was shaped like a human hand and embellished with two lions placed head to tail, while an Etruscan fibula from the eighth century was decorated with ducks. Dating from the seventh century b.c., elaborately decorated fibulae often had rows of lions or sphinxes along the catch plate, either carved in relief or soldered. The Greeks and Romans called them fibulae (Latin for brooch) and used some to fasten garments, while others were mainly omnamental. Coiled bronze pins, embellished with gold and several inches long, have been found in Egyptian tombs. Manville invented an automatic fourslide machine, which was the forerunner of machines used today.Įven though the current design is a modern one, the safety pin is an ancient fastener. ![]() However, the manufacture of its most common material, steel, has greatly improved, as has the mechanized process used in forming the pins. ![]() The design has remained virtually the same ever since. He patented the design in 1849 and sold his idea for $400. He designed a "safe pin" for securing clothing, which protected fingers from the sharp end. An indebted inventor named Walter Hunt sought a way to repay a $15 debt. A coiled piece of steel wire, sharpened at one end with a catch plate at the other, the modern safety pin is a device that can be traced back to New York City in about 1825.
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