What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
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
1. Correctly select the product a. Before use, confirm whether the mechanical properties of the product can meet the needs of use, such as the tensile strength of the screw and the guaranteed load of the nut. The length of the screw should be selected appropriately, and the 1-2 pitch of the nut will be exposed after tightening. b. Before use, check whether the threads are rough, and whether there is iron filings or dirt between the threads, which often lead to locking. c. The fasteners can be lubricated before use. It is recommended to use butter, molybdenum disulfide, mica, graphite or talc for lubrication. Generally, dipping wax is used for lubrication and anti-locking. [1] 2. Pay attention to the use method when using it. a. The speed and force of screwing in should be appropriate, not too fast or too large. Use a torque wrench or socket wrench as much as possible, and avoid using an adjustable wrench or an electric wrench. Excessive speed will cause the temperature to rise rapidly and cause lock-up. b. In the direction of force, the nut must be screwed in perpendicular to the axis of the screw. c. The use of washers can effectively prevent the problem of over-tightening.
The use of stainless steel screw lines: The hardness of stainless steel screw lines causes them to have different uses. Generally, they are used as small screws in life, but also as car screws and compression screws. They are widely used in normal life. Types of stainless steel screw lines: In appearance, screw lines are generally divided into fog surface spring lines and bright surface screw lines. The hardness of matte surface screw lines is higher than that of bright surface screw lines. For products with low appearance requirements and relatively high elasticity requirements. Paper, oxalic acid, fertilizer and other production equipment; photography, food industry, facilities in coastal areas, ropes, CD rods, bolts, nuts.
The flat key is simple in manufacture, reliable in operation, convenient in assembly and disassembly, and widely used. The flat key transmits torque by contacting the two sides of the keyway with the two sides, that is, the side is the working surface, so the main technical requirements for assembly are: to ensure the matching requirements between the flat key and the keyway of the parts on the shaft, and to transmit the movement smoothly and torque. The matching nature of the key and the keyway generally depends on the working requirements of the mechanism. The key can be fixed on the shaft or the hub, and can slide relative to another matching part (guide flat key); it can also be fixed on the shaft and the hub at the same time (ordinary flat key), and based on the size of the key, by changing the shaft The size of keyway and hub keyway can meet different matching requirements.
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
