New structure construction 1) For friction type high-strength bolt connections, slippage occurs when overloaded. But for grease-loaded bolts, this momentary slip is impossible. Grease-loaded bolts have the ability to withstand short-term overload. 2) If the plate thickness and the screw diameter can be maintained at an appropriate ratio, the grease-loaded bolt without pre-tension can provide the same resistance as the friction type high-strength bolt. 3) If the space for bolting is small, which requires each bolt to provide higher resistance, then a pre-tensioned grease-filled bolt can solve this problem. The resistance of the pre-tensioned grease-bonding bolt is the sum of two parts, one is friction; the other is the resistance provided by the resin. Therefore, under the more severe connection conditions, a small amount of pre-tensioned grease-filled bolts can provide relatively large resistance. 4) High-strength bolts require special equipment to handle the surface to achieve the desired coefficient of friction. If it is to be preserved, the painted surface must also guarantee the coefficient of friction of the design. For grease-loaded bolts without pre-tension, no surface treatment is required to ensure no slippage. High-strength bolts also require special tightening tools to ensure adequate pre-tensioning, which is not required for pre-tensioned grease bolts. 5) Demolition of grease bolts is difficult unless special preparations are made in advance. For example, a special separating agent is used to prevent the resin from sticking to the screw and the hole wall, while the high-strength bolt is easy to disassemble. The material cost of a grease-filled bolt includes the following aspects: 1) The cost of the bolt itself. 2) Preparation of the bolts and washers (drill holes in the nuts and prepare suitable washers. 3) Preparation and injection of resin. At present, there are a series of products of grease-insulated bolts and corresponding washers in Europe, and the grease-injecting equipment is not complicated, and the resin used for each bolt is very limited, so the material cost is not high. The labor cost of each grease bolt depends on the following aspects: 1) The total number of grease bolts. 2) The number of bolts per connection. 3) The accuracy of the bolt. 4) The size and length of the bolt. 5) Possible delays. Because the holes must be dry when filling (may require temporary rain and snow protection). The installation time of a grease-filled bolt is 12min. With grease-filled bolts, the number of bolts at the joint can be reduced, which also reduces the number of holes and bolts. The cost of itself. In addition, the lower screw hole accuracy also facilitates installation, which in turn reduces costs. The installation of the grease-filled bolts completes the installation of the grease-filled bolts in groups of two. One person injects grease and the other checks whether the resin overflows from the leak hole of the lower gasket. If the time for preparing the resin is added, it takes about 30 minutes to install a set of 20 grease-filled bolts when using a hand-press type injection device. If a long bolt or a large number of bolts are installed, the pneumatic injection device will perform better.
Tape Measure is a commonly used tool in daily life. What you often see is the Steel Tape Measure, which is a commonly used tool in construction and decoration, and it is also one of the necessary tools for the family. Divided into fiber tape measure, tape measure, waist circumference and so on. Luban ruler, Feng Shui ruler and Wen Gong ruler are also Steel Tape measures.
Henan liangjin tools co.,Ltd founded
1999, is a modern chemical measuring tool manufacturer integrating
scientific research, development, production and export sales. Abs Plastic Tape Measure,Plastic Coated Tape Measure,Plastic Tape Measure,Tape Measure Scale Henan Liangjin Tools Co.,Ltd , https://www.jtapemeasure.com