|Place of Origin:||Shanghai, China|
|Minimum Order Quantity:||30kg|
|Packaging Details:||spool, coil, carton or plywood case with plastic film according to clients' requirements|
|Delivery Time:||7-12 DAYS|
|Payment Terms:||L/C, T/T, Western Union, Paypal|
|Conductor Type:||Solid||Wire Shape:||Round/ Stranded|
|Number Of Wires:||7,19,37,61||Specification:||ASTM|
37*0.38 Stranded Wire/ Cable Nichrome Wire Coil with Straight Bright Surface
Detailed Description of Stranded Wire:
Stranded wire is extremely versatile and employed in a number of industrial, commercial, and consumer applications. While some applications require solid conductor wires and cables, stranded wire is often preferred for its greater degree of flexibility.
Stranded cables and wires are used heavily in industries which require a great deal of lifting, support, and tension such as aerospace, automotive, communications, chemical, electronics, defense, security, and medical industries. To suit the needs of these industries and more, stranded rope is increasingly specialized. If uncertain, wire rope suppliers should be consulted in order to select the proper wire and avoid potentially costly and dangerous mechanical failures.
Stranded wires are identified by listing both the number of strands and the amount of wires per strand respectively as well as the lay and pitch of the rope. Identification codes can also extend to specifics such as core type, workload limit, and more, listed in abbreviated form.
The connections, fasteners, fittings, and other hardware attached to the stranded wire are also important as they offer differing degrees of wire versatility in terms of fray prevention and connectivity.
For geometrical reasons, the lowest number of strands usually seen is 7: one in the middle, with 6 surrounding it in close contact. The next level up is 19, which is another layer of 12 strands on top of the 7. After that the number varies, but 37 and 49 are common, then in the 70 to 100 range (the number is no longer exact). Even larger numbers than that are typically found only in very large cables.
For application where the wire moves, 19 is the lowest that should be used (7 should only be used in applications where the wire is placed and then does not move), and 49 is much better. For applications with constant repeated movement, such as assembly robots and headphone wires, 70 to 100 is mandatory.
For applications that need even more flexibility, even more strands are used (welding cables are the usual example, but also any application that needs to move wire in tight areas). One example is a 2/0 wire made from 5,292 strands of #36 gauge wire. The strands are organized by first creating a bundle of 7 strands. Then 7 of these bundles are put together into super bundles. Finally 108 super bundles are used to make the final cable. Each group of wires is wound in a helix so that when the wire is flexed, the part of a bundle that is stretched moves around the helix to a part that is compressed to allow the wire to have less stress.
Like wire rope, stranded wire has three basic elements: wire filaments, strands, and cores.
The first components are the cold drawn rods of metal that are relatively small in diameter as compared to the rope as a whole.
These filaments are twisted or braided together to form a strand, or grouping of wires. The strands may consist of as few as two or as many as several dozen filaments depending upon the intended use of the finished product.
The core is the element around which the strands are wrapped in a helical pattern. Cores can be made of metal or fiber and the strands may be positioned around the core in either a clockwise or counterclockwise direction known as the lay.
The materials chosen for the wires, strands, and cores are crucial and must provide the appropriate strength, flexibility, and wear resistance for their intended use. Stainless steel cables are popular, as are a number of other steel cable types, because they provide specific desired characteristics such as strength and wear resistance.
Other materials such as copper and aluminum may be chosen for their good electrical conductivity whereas nickel alloys are chosen for electrical resistance.
The specific material employed in the construction of stranded wire is selected with regards to the application in which it will be used.
Other important considerations include diameter, difficulty of flattening, temperature resistance, and average lifespan.
Stranded wire is composed of a number of small wires bundled or wrapped together to form a larger conductor. Stranded wire is more flexible than solid wire of the same total cross-sectional area. Stranded wire is used when higher resistance to metal fatigue is required. Such situations include connections between circuit boards in multi-printed-circuit-board devices, where the rigidity of solid wire would produce too much stress as a result of movement during assembly or servicing; A.C. line cords for appliances; musical instrument cables; computer mouse cables; welding electrode cables; control cables connecting moving machine parts; mining machine cables; trailing machine cables; and numerous others.
At high frequencies, current travels near the surface of the wire because of the skin effect, resulting in increased power loss in the wire. Stranded wire might seem to reduce this effect, since the total surface area of the strands is greater than the surface area of the equivalent solid wire, but ordinary stranded wire does not reduce the skin effect because all the strands are short-circuited together and behave as a single conductor. A stranded wire will have higher resistance than a solid wire of the same diameter because the cross-section of the stranded wire is not all copper; there are unavoidable gaps between the strands (this is the circle packing problem for circles within a circle). A stranded wire with the same cross-section of conductor as a solid wire is said to have the same equivalent gauge and is always a larger diameter.
However, for many high-frequency applications, proximity effect is more severe than skin effect, and in some limited cases, simple stranded wire can reduce proximity effect. For better performance at high frequencies, litz wire, which has the individual strands insulated and twisted in special patterns, may be used.