What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
The retaining ring is divided into two types: shaft use and hole use. Its structural characteristics: The shaft retaining ring is a kind of retaining ring installed on the shaft groove, which is used for positioning and fixing of shaft end parts, and can withstand severe vibration and shock loads, but It is necessary to take anti-loosening measures and installation positioning; the hole is installed in the circular hole with an elastic retaining ring, which is used for the axial movement of the fixed parts. The outer diameter of this retaining ring is slightly larger than the diameter of the assembly circular hole.
The main operation method of the embedded knurled copper nut of the lock nut is injection molding. After heating, it is embedded into the plastic part or directly injection molded. If injection molding is used, the melting point of P/NYLOY/PET is above 200°C. , After the embedded nut is hot melted into the plastic part, the temperature rises rapidly. After injection molding, the plastic body rapidly cools and crystallizes and hardens. If the embedded nut temperature is still at a high temperature, it may fall to the place where the copper nut contacts the plastic part. Start to loosen or crack. Therefore, copper nuts are used instead of carbon steel nuts in the injection molding of embedded nuts.
Yueluo relates to a self-tapping screw according to the preamble of claim 1. A self-tapping screw is known from EP0623759B1, the ratio of the outer diameter to the smaller diameter of the self-tapping screw is about 1.25-1.5, the ratio of the outer diameter to the pitch lead is about 1.5-1.6 and the thread The flank angles of , are < 50° and ≥ 35°. EP0433484B1 proposes a self-tapping screw whose thread is provided with cutting teeth of approximately arcuate design, and the cutting edge and the thread crest are at the same horizontal position and are set in opposite directions. One purpose of Yueluo is to realize a general type of self-tapping screw so that it can be screwed particularly easily into holes drilled in concrete or other materials such as bricks and the like. According to Yueluo, this object is achieved by the features in the characterizing part of claim 1, and surprisingly, it has been found that the parallel arrangement of the flanks, ie with a flank angle of about 0°, will make screwing particularly easy when screwing in , especially if the diameter of the hole varies within an allowable tolerance. One reason may be due to the fact that there is no lateral pressure on the material screwed into the thread, even if threads of different depths are cut in concrete or other materials such as brick, chipped plywood, or hardwood. The thread cuts into the material over its entire width by cutting grooves. In particular according to the embodiment of claim 4 the material cut out when screwing in the screw can be discharged without any accumulation, the dependent claims reflecting many advantages of further embodiments.
Embedding of fasteners, especially screws. The main point of the structure is that it includes an annular base, one at the base and a plurality of cylindrical tubes on the base, and the cylindrical tubes and the cylindrical tubes on the base are connected by ribs. Cylindrical tubes are used as fixing holes and fastener pre-embedded holes respectively. The product is fixed on the formwork that needs to use screw points through the fixing holes. After the concrete is poured into the floor, the embedded screw parts are pre-embedded, and the floor has embedded screw holes for hanging the installation objects with screws. . Avoid future re-drilling damage to the wall and floor. Guangdong Yueluo Hardware Industry Co., Ltd. has a simple and scientific structure, easy pre-embedding, strong tensile strength and firmness.
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