Service HotlineThe middle pins on upright and horizontal pianos are also called balance pins. The middle pins are installed on the middle sleepers of the keyboard frame and play the role of fixing the keys. Generally, there are 88 keys in the piano. The pins are matched with the pin holes, and the keys are installed on each middle pin one by one through the pin holes. Due to the large number of middle pins and keys, in the production and installation process, in order to ensure the flatness of the 88 keys after installation, it is necessary to debug the middle pins and keys one by one, or add paper circles to the middle fixed part on the middle pins. The flatness of the 88 keys is kept the same. This debugging method is extremely cumbersome and increases the workload of debugging. Moreover, when adding paper circles, the keys need to be disassembled frequently. Due to the limitation of the installation space of the keys, it is troublesome to disassemble the keys, and it is easy to install and disassemble the keys many times. Damage to the pin holes on the keys, degrading the quality of the piano.
Among them, the pneumatic riveting machine is more commonly used. The pneumatic riveting machine is also equipped with a clamp for assembling the rivet. The existing clamp usually uses two rotating clamps for fastening and assembly, but the rotation easily causes the two clamps to buckle. Misalignment, thus affecting the assembly of the rivet.
T-slot convenient bolt that can be used for the middle port of the T-slot and directly realizes the assembly and tightening of the bolt and the nut. Technical Background At present, the bolts for T-slots are assembled from two side ports of the T-slots. When the length of the T-slot is long, it is time-consuming and laborious to install from the side port to the center port at the designated position. In addition, the two side ports of the T-slot are often blocked by other components, and the bolts for the T-slot cannot be installed or removed without disassembling other components. The utility model makes some improvements to the prior art. SUMMARY OF THE INVENTION The purpose of the present invention is to provide a T-slot convenient bolt with simple structure and convenient mounting and dismounting for the current situation that the existing T-slot bolts are inconvenient to install and disassemble.
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.
For common screw belts, please refer to the Central Taiwan Announcement No. 327442 Screw Belts (2) on February 21, 1998. It includes a main body, and there are multiple grooves on the side of the main body, which are used for locking screw tools to drive the belt. A toggler; and a plurality of nail grooves are arranged on the nail belt so that the screw planting is arranged in an arrangement, and the nail grooves are all provided with through holes, and the through holes extend downward with a ring to form a support portion for the screws; and the It is surrounded and provided with a plurality of cutting grooves, which is beneficial for the screw to be rotated through the nail groove; and it is characterized in that the nail groove is located on the inner wall surface of the surrounding and is provided with a plurality of lobes, and these lobes are implanted in the screw. In the nail groove, the leaflet supports the screw, so that the screws with different outer diameters are fully supported and positioned by the leaflet; and/or the upper part of the leaflet is inclined or curved, so that a depression is formed above the ring to support the screw The arc surface or tapered surface of the neck can make the screw more stable to be supported.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: hexagonal nuts wholesale, Daquan 304 stainless steel bolts, cup head socket head cap screws, black high-strength bolts and other products, we can provide you with suitable products for you Fastener Solutions.
