Service HotlineYueluo 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 13 the material cut out when screwing in the screw can be discharged without any accumulation, the dependent claims reflecting many advantages of further embodiments.
With the advancement of technology in various industries, the current structural design of screws has evolved from just simple locking to focusing on work efficiency during the locking process and not destroying the integrity of the objects to be locked. The new cases such as No. 556784 screw improvement and No. 289405 screw that integrates locking, stability, labor-saving, fast and multi-function which were previously designed and approved and published in the Central Taiwan Bulletin are the main representatives of screws. It is clear that It is learned that the two cases not only fully improve the shortcomings of the traditional simple locking screws, but also achieve the purpose of substantial improvement of the screws designed in each case in actual use.
However, Yueluo still feels that there should be room for improvement for the screw improvement and screw that integrates stability, labor, fast and multi-function in the above two cases; for example, No. 556784 screw improvement Although the rod has the function of cutting and collecting chips, when the screw starts to screw into the object such as wood, it is hindered by the hardness of the object's tissue, so the staff still needs to exert considerable force, resulting in the lock. In the solid operation, there is still a lack of difficulty in screw-in operation; another example, new cases such as No. 289417 screw that integrates locking, stability, labor-saving, fast and multi-function, although the rod has the structural function of cutting and chip removal, it is The rod part is screwed into the middle section to the rear section of the object. Since the debris cannot be discharged, the rod part pushes the outer part of the object to the surrounding tissue of the object, so that the object expands outwards and even seriously damages the appearance of the object.
Common types of common screws All kinds of common screws (20 pieces) a. Slotted: a word ( Minus ) b. Phillips: cross ( Plus ) c. Phil-Slot: a word / cross d. Hex Socket: hexagon socket e. One Way: One-way (can only be locked in, not out) A-4: Head Code/ head shape. a. Flat: Flat head (after locking, the top is flush with the work piece) b. Oval: salad head, O head, countersunk head screw unit of measure screw unit of measurec. Round: round headd. Pan: round flat heade. Truss: large round flat headf. Hex: hexagon head. A-5: Finish Code/Appearance treatment. Metric Self-tapping screw: Mark Tapping Type directly behind the product name. Ex: M3 x 6 –PPB, Tapping Type: M3 self-tapping screw, 6mm long, cross, round flat head, black plated. Generally, it is determined by product type or mark. For Sheet Metal or plastic parts. *Pitch = Threads per inch
(+): Cross slot (-): Slotted slot (T): Chrysanthemum slot (H): Hexagon socket (PZ): Bevel slot (+-): +- slot (Y): Y-shaped slot (H) : H-groove (L): Back-stop tooth (WIS): Single-moving spring washer (WIF): Single-moving flat washer (WIT): Single-moving external tooth washer (W2SF): Double-moving flat washer (W=6mm ): Washer outer diameter equal to 6mm (SUS): Stainless steel (Cu): Brass (Br): Red copper (8.8): Grade 8.8 screw (10.9): Grade 10.9 screw (12.9): Grade 12.9 screw (R): Other Notes
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