What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
National Standard 1 GB/T3103.3-2000 Fastener Tolerance Flat Washers 2 GB/T5286-2001 General Scheme of Flat Washers for Bolts, Screws and Nuts 3 GB/T9074.1-2002 Bolts or Screws and Flat Washers Assemblies 4 GB/ T9074.18-2002 Self-tapping screws and flat washers assembly 5 GB/T 95-2002 Flat washers C grade 6 GB/T96.1-2002 Large washers A grade 7 GB/T96.2-2002 Large washers C grade 8 GB/ T97.1-2002 Flat washer Class A 9 GB/T97.2-2002 Flat washer chamfered Class A 10 GB/T97.4-2002 Flat washer for screw and washer assemblies 11 GB/T97.5-2002 Flat Washers for self-tapping screws and washer assemblies 12 GB/T848-2002 Small washers Class A 13 GB/T5287-2002 Extra large washers Class C 14 GB/T4678.13-2003 Die-casting mold parts Part 13: Push plate washers 15 GB /T4605-2003 Rolling bearing thrust needle roller and cage assemblies and thrust washers 16 GB/T97.3-2000 Flat washers for pins 17 GB/T18230.5-2000 Flat washers for bolted structures quenched and tempered 18 GB/T9074 .5-2004 Cross recessed small pan head screw and flat washer assembly 19 GB/T9074.20-2004 Cross recessed hexagon head self-tapping screw and flat washer assembly 20 GB/T3762-1983 Sharp angle seal for tube fittings Washers 21 GB/T1231-2006 High-strength large hexagon head bolts, large hexagon nuts, and washers for steel structures Specifications 22 GB/T1230-2006 High-strength washers for steel structures 23 GB/T2861.10-2008 Die guides - Part 10 : Washers 24 GB/T5649-2008 Lock nuts and washers for pipe joints 25 GB/T94.3-2008 Technical conditions for elastic washers Saddle, wave elastic washers 26 GB/T3099.1-2008 Terms of fasteners threaded fasteners , pins and washers 27 GB/T10447-2008 Elements and tolerances of semicircular thrust washers for sliding bearings 28 GB/T94.1-2008 Technical conditions for elastic washers Spring washers 29 GB/T10446-2008 Dimensions and tolerances for full circle thrust washers for sliding bearings 30 GB/T93-1987 standard spring washer 31 GB/T94.2-1987 elastic washer technical conditions toothed, serrated lock washer 32 GB/T98-1988 stop washer technical conditions 33 GB/T849-1988 spherical washer 34 GB/ T850-1988 Cone Washer 35 GB/T851-1988 Split Washer 36 GB/ T852-1988 Square bevel washer for I-beam 37 GB/T853-1988 Square bevel washer for channel steel 38 GB/T854-1988 Single ear stop washer 39 GB/T7244-1987 Heavy spring washer 40 GB/T855-1988 Double lug Stop washers 41 GB/T7245-1987 Saddle spring washers 42 GB/T7246-1987 Wave spring washers 43 GB/T856-1988 Outer tongue stop washers 44 GB/T858-1988 Stop washers for round nuts 45 GB/T859- 1987 Light spring washer 46 GB/T860-1987 Saddle elastic washer 47 GB/T861.1-1987 Internal tooth lock washer 48 GB/T861.2-1987 Internal serrated lock washer 49 GB/T862.1-1987 External tooth Lock Washers 50 GB/T862.2-1987 External Serrated Lock Washers 51 GB/T955-1987 Wave Elastic Washers 52 GB/T27938-2011 Sliding Bearing Thrust Washers Failure Damage Terms, Appearance Features and Reasons 53 GB/T956.1 -1987 Conical Lock Washer 54 GB/T956.2-1987 Conical Serrated Lock Washer 55 GB/T28697-2012 Rolling Bearing Self-aligning Thrust Ball Bearing and Self-aligning Seat Washer Dimensions 56 GB/T9074.2-1988 Cross Groove Pan head screw and external serrated lock washer assembly 57 GB/T9074.3-1988 Cross recessed pan head screw and spring washer assembly 58 GB/T9074.4-1988 Cross recessed pan head screw, spring washer and flat washer assembly 59 GB/T9074.7-1988 Cross recessed small pan head screw and spring washer assembly 60 GB/T9074.8-1988 Cross recessed small pan head screw and spring washer and flat washer assembly 61 GB/T9074.9-1988 Cross recessed Countersunk head screw and conical lock washer assembly 62 GB/T9074.10-1988 Cross recessed half countersunk head screw and conical lock washer assembly 63 GB/T9074.11-1988 Cross recessed pocket hexagon head bolt and flat washer Assembly 64 GB/T9074.12-1988 Cross-recessed hexagon head bolt and spring washer assembly 65 GB/T9074.13-1988 Cross-recessed hexagon head bolt, spring washer and flat washer assembly 66 GB/T9074.15 -1988 Hexagon head bolt and spring washer assembly 67 GB/T9074.16-1988 Hexagon head bolt and serrated lock washer assembly 68 GB/T9074.17-1988 Hexagon head bolt, spring washer and flat washer assembly 69 GB/ T9074.26-1988 Spring washers for assemblies Ring 70 GB/T9074.27-1988 External Serrated Lock Washers for Assemblies 71 GB/T9074.28-1988 Conical Lock Washers for Assemblies 72 GB/T1030-1988 Inner Spherical Washers
On the other hand, when assembling many pin installation mechanisms, one end of the pin needs to be installed into the hole or arranged in the hole, and then the other end of the pin is applied to the pin through the pin installation mechanism, so that the pin is fixed in the hole. In the hole of the hole type product. This fixing method is not only extremely inefficient. And it is not possible to install multiple pins at once. Especially when exemplified at the other end of the pin, since there is nothing to hold the pin stable when the pin enters the hole type product, when force is applied to the other end of the pin, the pin can easily bend and damage the pin. .
Make further details to make the technical scheme of Guangdong Yueluo Hardware Industry Co., Ltd. easier to understand and master. As shown in Figure 1, Yueluo is a schematic diagram of the thread design structure of the plastic screw of Guangdong Yueluo Hardware Industry Co., Ltd. It can be seen from the figure that this creation mainly controls the tooth angle of the thread. Compared with the normal tooth angle of many self-tapping screws, which are 48 degrees, 60 degrees and 34.5 degrees, the tooth angle of Guangdong Yueluo Hardware Industry Co., Ltd. The profile angle is formed by a 30-degree asymmetrical thread I. In particular, the asymmetrical thread I has a forward thread angle greater than the reverse thread angle. A more preferred embodiment is an asymmetric thread. The tooth profile angle α of the in-line installation is 20 degrees, and the tooth profile angle β of the reverse installation is 10 degrees. With this narrower non-stacked thread, the radial pressure on the plastic material is effectively reduced. In addition, the connecting bottom surface 11 between the screw teeth is designed as a circular arc surface. In the process of forming the self-tapping thread, it is more conducive to the flow of the material and the formation of the thread, and at the same time, the material can be more closely matched with the screw. Moreover, the radial pressure of the casing is relatively uniform, and the formed threads are not easily damaged. Yueluo has been tested by a series of professional parameters. Compared with other traditional screws, the plastic screws designed by Guangdong Yueluo Hardware Industry Co., Ltd. have better radial pressure, shell deformation after installation, load distribution, installation torque, drawing The force distribution, the strength of the pull-out force and the mounting torque range all show advantages. In particular, it can be installed with less torque to achieve the same clamping force and pulling force. Compared with a specific parameter, the thread strength of Delta-PT is 387N, while the thread strength of Guangdong Yueluo Hardware Industry Co., Ltd. reaches 452N. Yueluo can understand the plastic screw structure and implementation of Guangdong Yueluo Hardware Industry Co., Ltd. detailed above. It can be understood that through the improvement of the special thread structure, the radial pressure and installation torque during screw installation are reduced, and the damage to the plastic hole is reduced; And the pull-out resistance of the screw is increased, and it is not easy to appear loose in the assembly. At the same time, the design of the bottom surface of the connection between the threads of the arc optimizes the flow of the material of the installation object, which improves the integrity of the installation connection.
To sum up, the chip nut provided by Guangdong Yueluo Hardware Industry Co., Ltd. has a circle of serrated teeth 1011 protruding outwardly on the edge of the welding end face 101. During welding, the excess solder overflows and flows to the periphery. In the gap between the serrated teeth 1011, on the one hand, the solder on the welding end face 101 can be made uniform, so as to ensure that the welded chip nut is neat and beautiful; The welding area is increased, and the firmness and reliability of the welding are improved.
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