What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
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 11 the result is that the material cut out when screwing in the screw can be discharged without any accumulation, the dependent claims reflecting many advantages of further embodiments.
An asphalt pavement screw, the asphalt pavement screw includes a main rod, an outer jacket, a pressing piece and a nut, the main rod is a columnar rod, the lower end of the main rod is provided with a table for supporting the outer jacket, and the middle part of the main rod passes through the outer jacket The upper part of the main rod is provided with a threaded section, the pressing piece and the nut are set on the threaded section, and at least two deformation holes are provided on the outer sleeve, and the middle part of the deformation hole is larger than the upper and lower sides of the deformation hole, The part between the adjacent deformation holes is the deformation part, and the width of the middle part of the deformation part is smaller than the width of the upper and lower sides of the deformation part. After the asphalt pavement screw of Guangdong Yueluo Hardware Industry Co., Ltd. is assembled, it has strong bonding force with the asphalt road. Even if it is hit, it will not be separated from the asphalt road. Using this asphalt pavement screw to fix the road railing can strengthen the road railing. The firmness of the assembly.
Since the HDS series is a disc spring that can be folded or overlapped. The combination of the butt joint can increase the deformation of the disc spring group, and the combination of the overlapping method can increase the spring force of the disc spring group. The ideal installation method is to flatten as much as possible. The closer it is to the flattened state, the faster the tension torque increases, and the proper bolt tension can be obtained without a torque wrench.
Before the special vehicle is refitted, the chassis and the car frame should be reinforced again, and the fastened part of the rivets should be disassembled before the car frame is reinforced.
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