① Nominal thread outer diameter (thread specification): divided into metric system and inch system. Metric thread → common specifications are 2; 2.3; 2.5; 2.6; 2.9; 3; 3.1; 3.5; 4; 4.2; 4.5; The unit is mm (millimeters). Inch thread→ Common specifications are 2#;4#;6#;8#;10#;12#;1/4;7/32;5/16;3/8;1/2 ;9/16;3/ 4. The unit is in (inches). ② Number of teeth/pitch: Definition of number of teeth → the number of teeth lines in one inch (25.4mm) length. Pitch Definition → Distance value between two adjacent threads. Conversion of number of teeth and pitch of teeth → pitch of teeth = 1 inch/number of teeth ③Nominal length: divided into metric system and inch system. Metric Nominal Length → Common values are 5, 6, 6.5, 7, 8, 9, 9.5, 10, 11, 12, 13, 14, 15, 16, 18, 19, 20, 21, 25, 28, 30, 31 , 32, 35, 40, 42, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120. The unit is mm (millimeters). Imperial Nominal Length → Common values are 1/4, 5/16, 3/8, 7/16, 1/2, 5/8, 3/4, 1, 2, 3. Units: in (inches). ④Head type: use letters to indicate the type of head type, please refer to the previous classification of commonly used screw head types. ⑤Tooth type/tail type: Use letters to indicate the type of tooth type/tail type, please refer to the previous Commonly used screw thread/tail type classification. ⑥Groove type: Please refer to the previous section Category of common screw groove types of our company. Cross-slotted or non-slotted (such as punched hexagon head screws) do not need to be marked here, and other groove types need to be described in words. ⑦Special labeling: In general, no labeling is required. When expressing its characteristics, it is described in words at this position. For example: the specification name of the screw is described as 4-0.7x70PM±tooth length 35, which means 4 is the nominal diameter of the screw thread, 0.7 is the pitch, 70 is the nominal length of the screw, and P means its The head type is a pan head, M means its tooth type/tail type is a wire thread type, ± means its groove type is ± groove and can also be expressed by plus or minus groove. Tooth length 35 is special Mark, specify the thread length value of this screw.
Sometimes, the iron screws are often seen broken, and sometimes, the stainless steel screws are also seen broken. But generally speaking, stainless steel screws rarely break. Because the stainless steel screw wire itself is relatively hard. But under certain circumstances, stainless steel screws can still break. So what are the main reasons for stainless steel screws to break? The reasons for the fracture of stainless steel screws are as follows: 1. The quality of raw materials used for stainless steel screws is poor, and the quality of stainless steel screws is not good. There are many impurities, impure, resulting in insufficient hardness of stainless steel screws. 2. The production process of stainless steel screws. For example, stainless steel screws with eccentric head and eccentricity, and the Q value is too deep and the R position design is too small during the down punching operation during production. 3. The customer uses too much force when using stainless steel screws. Generally, you do a torque test to see how much the minimum breaking force is, and then adjust the torque. Of course, stainless steel screws must be broken for more than three reasons. But the above three reasons are the main reasons for the fracture of stainless steel screws. When the stainless steel screw is found to be broken, it can be checked step by step. Find out what's causing it.
In the current plastic matrix, it is common to use self-tapping screws or add copper inserts during injection molding. The former has poor strength, and the threaded hole is easy to crack; the processing cost is high, the injection molding efficiency is low, the labor cost and manufacturing cost are increased, and the insert is easy to slip and crack on the plastic, and the thread strength of the copper insert is not as high as that of the iron nut.
In order to achieve the above purpose, Guangdong Yueluo Hardware Industry Co., Ltd. provides the following technical solutions: self-expanding semi-solid installation rivets, used for connecting and perforating two or more units of parts, including top core and rivet body, characterized in that : The top core lock slot opened on the concentric sheath along the longitudinal direction is snapped into and screwed and fixed in the concentric sheath, the top core extends downward into the top core rotary sleeve, the concentric sheath The sleeve is connected with the upper sealing sleeve of the lower body and is connected with the longitudinal axis, a hollow body is arranged below the rivet body, a joint is installed under the hollow body, and a supporting foot is connected to the joint, and the supporting foot and the turning The folding clips are staggered and distributed, the folding clips are concave-convex inclined surfaces, and the supporting feet are slidably connected with the folding clips.
Spring washers are often called spring washers in the screw industry. Its materials are stainless steel and carbon steel, and carbon steel is also iron. The commonly used spring washers are M3, M4, M5, M6, M8, M10, M12, M14, M16. These specifications are more commonly used. The national standard for spring washers is GB/T 94.1-87, which specifies standard spring washers with a size of 2-48mm. Reference standard GB94.4-85 Elastic Washer Technical Conditions Spring Washer
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: three-piece fish scale expansion tube screws, hexagon head thin shank bolts, spot welding pressure welding hexagon nuts, GB858 and other products, we can provide you with The right fastener solution for you.