What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Fasteners are a type of mechanical parts that are used for fastening connections and are widely used. All kinds of fasteners can be seen on all kinds of machinery, equipment, vehicles, ships, railways, bridges, buildings, structures, tools, instruments, meters and supplies. It is characterized by a wide variety of specifications, different performance uses, and a very high degree of standardization, serialization and generalization. Therefore, some people also refer to a type of fasteners with existing national standards as standard fasteners, or simply as standard parts. Fasteners are the most widely used mechanical foundations. With my country's entry into the WTO in 2001, it has entered the ranks of major international trade countries. my country's fastener products are exported to many countries in the world, and fastener products from all over the world are also pouring into the Chinese market. Fasteners, as one of the products with the largest import and export volume in my country, are in line with international standards, which have important practical significance and practical significance for promoting Chinese fastener enterprises to go to the world and promoting fastener enterprises to fully participate in international cooperation and competition. strategic significance. Due to the specifications, dimensions, tolerances, weights, properties, surface conditions, marking methods, and specific requirements of items such as acceptance inspection, marking and packaging for each specific fastener product.
The earliest rivets were small pegs made of wood or bone, and the earliest metal variants may be the ancestors of what we know as rivets. They are without a doubt the oldest known method of joining metals, dating back as far as the earliest use of malleable metals, eg: Bronze Age Egyptians riveted the six wooden sectors of the outer lines of a slotted wheel with rivets Fastened together, after the Greeks had succeeded in casting large statues in bronze, the parts were riveted together with rivets.
The cylindrical pin is mainly used for positioning and can also be used for connection. It is fixed in the pin hole by means of interference fit. Cylindrical pins used for positioning are usually not subject to load or a small load, the number is not less than two, distributed in the symmetrical direction of the overall structure of the connected parts, the farther the better, the pin is in each connected part The length is about 1-2 times the minor diameter. Cylindrical pins can also be used as shafts, and a straight shaft can also be used as cylindrical pins or even centering pins. So what's the difference between a shaft and a pin? The shaft can be used to transmit torque, bear bending moment and torque, and the cylindrical pin can be used for positioning, bear extrusion force and shear force. In a sense (such as small equipment), cylindrical pins can also be used as shafts.
At present, there is an anti-theft T-bolt in the prior art, which is composed of a screw rod and a bolt head connected with the screw rod; the screw rod is composed of a polished rod and a threaded rod; a concave hole is provided at the bottom end of the screw rod; cylindrical, and the diameter of the cylindrical bolt head is larger than the diameter of the screw. When the above-mentioned anti-theft T-bolts are in use, the user usually hammers the concave hole at the bottom end of the screw with a hammer or other tool to deform it, destroy the thread structure on the screw, and fix the nut with a deformed object, so as to achieve anti-theft. Features
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