High-strength fastener materials mainly include ML35, 35K, ML40Cr, ML35CrMo steel, etc., of which 75ML35CrMo steel is imported. The main problems of the material are box segregation, decarburization, cracks and so on. The material needs to be spheroidized and annealed before cold forming, and the annealing is carried out in an oil furnace. There is no protective atmosphere in the furnace, and there is a decarburization phenomenon. 1.2 The high-strength fasteners, mainly grade 12.9, are quenched and tempered on the chain casting furnace production line. The temperature and atmosphere in the furnace are controlled by computer, and Rx gas is used as a protective atmosphere. Heating and anti-oxidation and decarburization can be effectively controlled, and the quality of the fasteners is intact during the heating process. The high-strength fasteners mainly of grade 8.8 are quenched and tempered on the vibrating hearth furnace. Affected by the structure of the vibrating hearth furnace, the sealing performance of the furnace is poor, the Rx atmosphere is not easy to control, the temperature difference of the furnace is large, and the parts are heated in the furnace. The collision and the length of time are inconsistent, and the quality of the fasteners during the heating process is poor, and there are phenomena such as decarburization, bumps, and uneven heating.
Bolts with low hardness and strength. Generally, ordinary bolt materials are produced with ordinary screw wires. The hardness, strength, tensile strength and torsion force of ordinary bolt materials are not very high. High-strength bolts generally refer to high-strength bolts. Its own screw material, bolt material, and bolt material are relatively good, and the hardness is relatively high, and after the production is completed, the bolts will be hardened. Make the bolts meet the grade strength requirements of high-strength bolts.
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.
The grooved embedded parts are pre-embedded in concrete, and then placed in the groove with T-bolts. After adjusting the fixed position, the fixed object is locked with a nut to achieve the fixing effect. When the grooved embedded parts are embedded vertically in the concrete or at a certain angle to the horizontal line, the T-bolts are likely to move in position before they are tightened. In particular, when fixing heavy equipment, multiple T-bolts are required, and multiple groups of workers are required to help and positioning is difficult, and the installation process is complicated.
In general, the electroplating of combination screws generally refers to the de-plating of iron combination screws. Electroplating is divided into environmental protection and non-environmental protection. Commonly used combination screw electroplating colors include green color zinc, green blue zinc, green white zinc, green nickel, red color, white zinc, white nickel, etc. Cross recessed combination screws, hexagonal combination bolts and self-tapping combination screws are used in the same way as the corresponding cross recessed screws, hexagon head bolts and self-tapping screws. The main feature of these combination screws is that they are equipped with corresponding washers, which are very convenient to use.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: super long ceiling screws, flower tooth washers, small yellow croaker bolts, step nuts and other products, we can provide you with suitable fastener solutions for you.