The "General Technical Conditions for Anti-theft Security Doors" implemented on April 1, 2008 stipulates that the anti-theft door must have a minimum anti-destruction time of at least 6 minutes. According to the new national standard, the security door locks should be able to open even if the cylinder is drilled, the lock body is disconnected to break the lock, or the tools are inserted through the upper and lower clearances, and the lock tongue is released. Door leaf. The above-mentioned so-called 'brand-name anti-theft door' apparently failed to meet the standards of the new national standard. Anti-theft doors are related to home security and are the must-see anti-theft care products for every city's residents. However, according to the author's observation on websites such as China Consumer Network, the quality of anti-theft door has not been reduced due to the promulgation of the "General Technical Conditions for Anti-theft Security Doors." According to incomplete statistics, complaints are mainly in the following areas: First, theft The quality of the door failed to pass the inspection. Second, no one came to the door after the repair. The third was to evade the responsibility after the loss. The fourth was the use of fire doors and other counterfeit doors. In fact, in the final analysis, the quality of the security door is still a problem. The "General Technical Conditions for Security Doors" has clearly defined the quality of anti-theft doors. Consumers can look at the four 'standards' with wide eyes during their purchase: The first is to look at the level of damage by the length of time, the thickness of the sheet and other indicators. The new standard reclassified the anti-theft security products of anti-theft door products and adjusted the anti-theft security level to four levels of 'A', 'B', 'C', and 'D', with A being the highest level and decreasing accordingly. The vandalism prevention time of the anti-theft door is also progressively reduced. The minimum D-class level is at least 6 minutes. Look at the thickness of the steel plate of the door leaf. Grades A, B, C, and D should reach 2 mm, 2 mm, 1.8 mm, and 1.5 mm, respectively. The thickness of the steel plate is directly related to the anti-theft security performance of the security door. Three look at the locks. According to the new standard, the security door locks should be capable of breaking the lock cylinder during the tamper-proof time, breaking the lock body connector to disassemble the lock tool, or inserting the tool through the upper and lower clearances to release the lock tongue. Open the door leaf; the lock point between the door frame and the door leaf shall be no less than 12, 10, 8 and 6 respectively according to the anti-theft security level A, B, C and D; the main lock tongue of the security door shall extend the effective length Should not be less than 16 mm, and there should be a tongue stop device. Four look at the mark. The new standard also adds content that can help consumers identify the authenticity of the security door, that is, requiring the security door should have a permanent fixed mark. The security door marking consists of 3 parts. The marking symbol is pinyin letters. From left to right, they are the anti-theft security code (FAM), anti-theft security level and corporate custom features (including the enterprise code and product code). Among them, the anti-theft security level mark is permanently fixed on the side of the inner hinge at a height of about 160 cm from the ground. The 'metal doors', 'steel doors', 'entrance doors' are not security doors, consumers should pay attention to polish their eyes when buying, do not be fooled by businesses. Security door plate entrance decoration restaurant decoration company Thin wall ball bearings are simple in structure and easy to use. Mainly used to bear radial load, but when the radial clearance of the bearing is increased, it has a certain performance of Angular Contact Ball Bearing and can bear combined radial and axial load.
Thin wall ball bearings have a bearing inner diameter and outer diameter ratio less than a specified value. The ratio of bearing outer diameter to bearing inner diameter is 1.25 or less. It is called thin wall ball bearings, which means that the outer diameter-inner diameter value of the bearing is very small and the bearing wall is very thin.
When the speed is high and thrust ball bearings are not suitable, thin wall ball bearings can also be used to bear pure axial loads. Compared with other types of bearings of the same size, this type of bearing has a small friction coefficient and a high limit speed. But it is not impact resistant and not suitable for heavy loads.
The precision required by thin wall ball bearings is very high, because the wall is very thin, so the weight it can carry is also very low, and the impact resistance is very poor, so this must be selected according to the use environment!
Characteristics
The specific use of thin wall ball bearings:
Model airplanes, remote control cars, machine tools, motors, water pumps, agricultural machinery, textile machinery, laser printers, instruments, measuring instruments, electronic accessories, motors, motors, etc.
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