Among the wide range of fasteners offered on the market by manufacturers, one of the most popular is wing nuts. Such fasteners are especially common in the construction industry, and are also widely used in mechanical engineering. Also, this type of fastener is known as a coupling nut. This article is dedicated to her.
Design Features
The wing nut has special petals or antennae designed to be screwed in or unscrewed without the use of any additional tool. In other words, you can install or remove this fastener manually. Otherwise, wing nuts, like the rest, have an internal thread.
The use of such nuts is justified for obtaining connections that, due to the peculiarities of operation, are subject to frequent assembly and disassembly.
Varieties of tie nuts
Wing nuts have a variety of classifications. This type of fastener is divided into the following types:
- According to the shape of the antennal petals, nuts are of American and German types. American nuts are cold-formed and have rectangular lugs. The German type nuts have rounded lobes and are either forged or cast. This type, although more expensive due to the manufacturing method, is also more convenient to use.
- According to the material used. For their manufacture, steel, brass, cast iron alloys are most common. American nuts are made from steel and brass. German wing nuts, given the way they are made, are made from cast iron.
- By diameter. The diameter of the coupling nuts can be measured with or without lugs. The most common fastener has a diameter of 100, 70, 85 mm.
- By bearing load. The permissible load on nuts of this type varies from a couple of kilograms to several tens of tons. This explains their use in engineering and construction.
- According to strength class. This parameter will be determined by the environment where this type of fastener is planned to be used.
- By design features. There are nuts with a support platform and without it. The presence of a support pad increases the rigidity of the nut. Also, at the very base of the nut, it can have a chamfer, which makes it easy to screw it onto the tie bolt without jamming. In addition, the petals of the nut may have special holes for sealing.
GOSTs for wing nuts
The design and dimensions of nuts of this type used in practice must comply with GOST 3032-76. According to this release documentwing-type fasteners with internal thread diameters from M3 to M24 are allowed. The most popular is M6 threaded fasteners. The manufacture of fasteners with M14 and M20 threads is not recommended by this GOST. This GOST indicates all the parameters for the corresponding fasteners.
According to the provisions of GOST, nuts can have coarse and fine thread pitch. The coarse thread pitch is in the range of 0.5–3 mm. For fasteners with M6 thread, it is 1 mm. Fine pitch only has fasteners with threads from M8 to M24.
You can familiarize yourself with the design of this type of fastener in detail by studying GOST 3032-76.
Foreign analogues
An analogue of fasteners produced in Russia according to GOST 3032–76 is fasteners of the DIN315 standard, produced in Germany.
The key dimensions of foreign nuts according to DIN 315 are:
- d - define the thread;
- h - height of the nut to the top edge of the "lugs";
- e - width with "ears".
Conclusion
As practice shows, the production of fasteners of such a complex shape requires the availability of appropriate and at the same time expensive equipment. In addition, a significant disadvantage of such nuts is the low strength of the formed fastening. Wing nut connections require careful planning in advance.
