What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
The conventional auger bit structure 1 includes a rod body 11, a screw head 12 provided on one end of the rod body 11, a drill tail 13 provided on the other end of the rod body 11, and a plurality of threads 14 arranged around the rod body 11; Wherein, the periphery of the drill tail 13 defines a parting line 15, and the parting line 15 makes the drill tail 13 symmetrically divided into a side 131 and a side 132, and a cutting end 133 is formed at the junction of the end of the side 131 and the end of the side 132, respectively. The cutting end 133 is concavely provided with a quarter-turn chip flute 134 in the same direction of the helix, and the edge 132 continues the chip flute 134 and has a quarter-turn chip flute 135 with different helical curvatures. , by connecting the chip groove 134 and the chip groove 135 through different helical curvatures, the drill tail 13 can form a symmetrical and complete chip groove of 189 degrees.
The technical solution adopted by Guangdong Yueluo Hardware Industry Co., Ltd. to solve its technical problems is a special pull rivet for railway freight cars, which has a pull rivet body and a collar. The rod body is composed of polished rod section, locking ring groove section and tail thread section from top to bottom. Protectors are provided at the tail thread section to prevent rust and bad teeth in the tail thread section during use. , collision deformation, etc. Specifically, the tail thread segment has an external thread or an internal thread, and the protective member is a nut or a bolt.
Pedicle screws can be divided into four types: one-way short-tail screw, one-way long-tail screw, universal short-tail screw and universal long-tail screw. Pedicle screws can effectively complete the three-column fixation of the spine and are clinical The most widely used internal fixation method for the treatment of spine-related diseases. Due to the different types of pedicle screws, four different screwdrivers are required to complete the screw insertion. However, the implantation of pedicle screws is performed in a complex three-dimensional space, which has high difficulty and risk. Mis-implantation of screws may cause instability of the internal fixation frame in the early stage, and may cause false joint formation in the later stage. Therefore, in the process of spinal internal fixation, it is necessary to ensure the accurate implantation of pedicle screws is the key to the success of the entire spinal internal fixation, and the selected implanted instruments are particularly important.
The retaining ring is a ring-shaped body with an opening, and the traditional processing method is stamping. That is, a plate-shaped material is selected and punched out on the plate-shaped material (a circular body, and then the middle of the circular body is punched to form a ring-shaped ring body.) The punched material in the middle cannot be used again. This results in a waste of material.
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
