What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Stamping die is a special process equipment for processing materials into parts in cold stamping processing, called cold stamping die. Stamping is to use the die installed on the press to apply pressure to the material at room temperature to make it produce Separation or plastic deformation to obtain the required parts of a pressure processing method, the technology generally used is to make corresponding holes and punches on the template, this method cannot meet the requirements for small batches and short delivery time products , the relative cost is relatively high, so a rivet die structure is required to improve the above problems.
1. For low strength (below 500 N/mm2 or below 60000 psi) bolts use general soft steel, generally use SAE 1008 or JIS SWRM 8 (or SWRCH 8). 2. Lower strength (600 N/mm2 or 74000 psi) ) bolts use general soft steel, but limited carbon content grade, generally use SAE 1010 - 1015 or JIS SWRM 10 - 15 (or SWRCH 10 - 15). .3. Higher strength ( 800 N/mm2 or 125000 psi ) bolts of medium carbon steel, low carbon boron steel plus quenching and tempering, generally use SAE 1035 - 1040 or SWRCH 35K - 40K. 4. High strength (900 N/mm2 or more or 150000 psi or more) bolts use medium carbon Alloy steel or low carbon boron steel, in terms of application, if the metric Class 10.9 uses low carbon boron steel, the imprint should be added under the series imprint to become 10.9, and the imprint of the inch 8.2 grade is also used with the general Grade 8 bolts The imprint is different for easy identification. High-strength bolts made of low carbon boron steel cannot be used in high temperature conditions. The design strength exceeds Class 12.9 or ASTM A574 ultra-high strength bolts are limited to medium carbon alloy steel plus quenching and tempering. The performance grades of bolts for steel structure connection are divided into more than 10 grades such as 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9, etc. Among them, the bolts of grade 8.8 and above are made of low-carbon alloy steel or medium-carbon steel and are heat-treated (quenching, tempering), commonly known as high-strength bolts, the rest are commonly known as ordinary bolts. The bolt performance grade label consists of two parts of numbers, which represent the nominal tensile strength value and yield ratio of the bolt material respectively. For example, a bolt with a performance level of 4.6 means: 1. The nominal tensile strength of the bolt material is 400MPa; 2. The yield ratio of the bolt material is 0.6; 3. The nominal yield strength of the bolt material is 400×0.6=240Mpa . Performance level 10.9 high-strength bolts, after heat treatment, can achieve: 1. The nominal tensile strength of the bolt material is 1000MPa; 2. The yield ratio of the bolt material is 0.9; High-strength bolts, processing and manufacturing problems are compared Small, general fastener manufacturing companies can master the manufacturing process; but problems are prone to occur in material selection and heat treatment. Material selection is the primary link. Various alloying elements have a great influence on the properties of the material, and the material must be subjected to spectral composition analysis; secondly, the fracture problem and the choice of heat treatment process have a great influence and are very important. Dealers and traders must control the inspection and performance testing links; automotive fasteners have high requirements and must carefully control the quality.
Here Yueluo eliminates the drawbacks. The purpose of Yueluo is to provide a locking screw by which the gap existing between the locking screw and a transverse hole in a locking screw can be eliminated. Yueluo achieves the proposed object with a locking screw, which has the features of claim 5 . The line connecting the centers of gravity of the respective axially continuous orthogonal cross-sectional areas of the locking screw is regarded as a line. The advantage achieved by Yueluo can basically be seen that, due to the locking screw of Yueluo, the gap between the horizontal hole of the screw and the locking screw can be eliminated. Other advantages are as follows - the insertion accuracy and surgeon time spent remain within the range to date; - the strength of the locking screw is maintained; and - the extraction of an expired broken screw is assured. The further composition of Yueluo and Yueluo is explained in more detail below by means of schematic diagrams of parts of various embodiments.
At present, drum brakes are usually used for rear brakes of automobiles, and pump parts assemblies are widely used. The traditional assembly method is to use tools such as screwdrivers and retaining ring pliers for assembly. The disadvantage is that the assembly efficiency is low, the accuracy is average, and assembly quality problems are prone to occur, which affects the performance of the product assembly. Now take the brake wheel cylinder assembly with automatic clearance adjustment mechanism produced by our factory as an example to illustrate the installation of the elastic retaining ring
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
