What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
China is the world's largest producer of carbon steel fasteners such as screws, nuts and bolts, and the EU is a major market for these products. In January 2009, the EU decided to impose anti-dumping duties of 26.5% to 85% on Chinese carbon steel fastener products. On July 31 of the same year, China resorted to the relevant EU legislation and anti-dumping measures to the WTO dispute settlement mechanism. The case became China's first lawsuit against the EU at the WTO. On July 15, 2011, the WTO Appellate Body issued a report and finally ruled that China won the case in the trade dispute with the European Union on fasteners. The head of the Department of Treaty and Law of the Ministry of Commerce of China welcomed the ruling on the 16th, and said that China's victory in the case is of great significance, which will help improve the competitive environment for Chinese companies in the international market including the European Union, and will also strengthen the WTO members' interest in the case. Confidence in WTO rules and the multilateral trading system. This is not only a victory for China's industry, but also a victory for WTO rules, the official said. The WTO Appellate Body found in its ruling report issued on the 15th that Article 9(5) of the EU's Basic Anti-dumping Regulations on individual tax rates violated WTO rules; at the same time, the Appellate Body overturned some of the panel's rulings and supported China's position , ruled that the EU's anti-dumping measures against Chinese screws, nuts, bolts and other carbon steel fasteners also violated WTO rules in terms of domestic industry identification, normal value and fair comparison of export prices. The head of the Treaty and Law Department of the Ministry of Commerce of China said that the EU is one of the WTO members that has initiated the most anti-dumping investigations against Chinese products in the world. unfair treatment. He said that China hopes that the EU will cancel the legislation and discriminatory anti-dumping measures that are inconsistent with WTO rules as soon as possible, treat Chinese export enterprises fairly, and effectively safeguard free trade and fair competition.
The common riveting techniques of non-blind rivets are divided into cold riveting and hot riveting. Cold riveting is a riveting method that uses a rivet rod to partially pressurize the rivet, and continuously swings around the center or the rivet is forced to expand until the rivet is formed. The common cold riveting methods are the pendulum riveting method and the radial riveting method. The pendulum rolling riveting method is easy to understand, and the rivet head only swings and rolls in the circumferential direction.
Due to its convenient operation, quick-release screws are widely used in aviation recording equipment, such as the operation panel on the central console of the aircraft, the upper operation panel, etc. However, the assembly of quick-release screws needs to be assembled in sequence. Springs and quick-release screw rods, usually the quick-release screw crimping tools provided by external suppliers can only crimp some small-sized quick-release screws, or custom-made quick-release screw crimping tools for a certain product, time and cost are very high, so it is necessary to design a quick-release screw assembly device for general aviation airborne equipment.
On the surface of the mounting hole on the connector, a 90-degree conical socket is machined, and the head of the flat machine screw is in the socket and is flush with the surface of the connector. Flat machine screws are also used in some occasions with semi-circle head flat machine screws, which are more beautiful and are used for places where a little protrusion is allowed on the surface. Screws play the role of connecting two or more objects and are an indispensable necessity in daily life or industrial manufacturing. There are countersunk head bolts (with grooves) and countersunk head bolts (with tenon).
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