What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
NPT, PT, G are all pipe threads. NPT is the abbreviation of National (American) Pipe Thread, which belongs to the American standard 60-degree taper pipe thread, which is used in North America. National standards can be found in GB/T12716-1991 PT is the abbreviation of Pipe Thread, which is a 55-degree sealed conical pipe thread, which belongs to the Whitworth thread family and is mostly used in Europe and the Commonwealth of Nations. Commonly used in water and gas pipe industry, the taper is specified as 1:16. The national standard can be found in GB/T7306-2000 G is a 55 degree non-threaded sealing pipe thread, which belongs to the Whitworth thread family. Marked as G stands for cylindrical thread. National standards can be found in GB/T7307-2001 In addition, the 1/4, 1/2, 1/8 marks in the thread refer to the diameter of the pipe, and the unit is inches. People in the industry usually refer to thread size in points, 1 inch equals 8 points, 1/4 inch is 2 points, and so on. G seems to be the general name for pipe threads (Guan), and the division of 55 and 60 degrees is functional, commonly known as pipe circle. That is, the thread is machined from a cylindrical surface. ZG is commonly known as pipe cone, that is, the thread is made of a conical surface. The general water pipe joints are like this. Rc means conical internal thread ZG means taper pipe thread, 3/4 means inch mark, which is 3/4 inch conical pipe Thread, there is in the Hardware Manual. The national standard stipulates that the major diameter of ZG 3/4 thread is 26.44 mm. Please refer to Metric, American and British Thread Standard Manual (Third Edition). Its representation method should be: ZG 3 /4″. Among them (〃) is the representative symbol for inches. One inch is equal to 8 inches. The origin of 3/4 is 6/8=3/4. Commonly known as 6 points. Similarly, the major diameter of ZG 1/2″ thread≈21 mm. Commonly known as 4 points. ZG 1″ thread diameter ≈ 33 mm. Commonly known as 1 inch. ZG 1 1/2″ thread pipe outer diameter ≈ 48 mm. Commonly known as 1 inch and a half. Taper pipe thread is very similar to pipe thread, the difference is Only in the taper. Note that the basic size of the pipe thread and ordinary thread is different. DN is the nominal diameter
As we all know, when installing the outdoor unit of the air conditioner, most of the installers need to hang it on the outer wall. When tightening the machine foot screws, they all need to lean out of the window or climb out the whole person, and use a wrench to tighten it. . Therefore, it is difficult for the installer to operate, and it is easy to drop the installation materials such as screws and nuts, which is not only a waste of materials, but also easy to hurt personnel. The purpose of Guangdong Yueluo Hardware Industry Co., Ltd. is to solve the above problems, and provide a safe and labor-saving air conditioner outdoor unit machine foot screw installer that the installer does not have to lean out of the window or climb out of the room, and the installation materials are not easy to fall.
In the prior art, there are also automated equipment for riveting and assembling of hardware and handles; however, for the existing automated equipment, how to automatically and efficiently realize rivet feeding is particularly important.
Flat washers are frequently used in mechanical connections. They are usually placed between the nut or screw head and the connected parts to prevent the screw or nut from loosening during use. The upper and lower end faces of conventional flat gaskets are mostly smooth planes, with a single structure and poor compressive capacity. When assembled with a nut or screw, the pressure on the flat washer is increased, and when it is closely rubbed with the nut or screw, it is prone to breakage, which greatly affects the quality of the product.
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