Melamine prices rise
Hexagon Bolt refers to the fastener composed of head and screw. According to the material, the bolt can be divided into iron bolt and stainless steel bolt, namely hexagon head bolt (partial thread) - C grade and hexagon head bolt (full thread) - C grade. Hex Bolt,Hex Bolts Cnc,Din933 Black Hex Bolts,Hex Bolts Head Screw With Dog Point Suzhou Gubao Screws Co.,Ltd. , https://www.gbscrewes.com
Looking at the price increase, the biggest increase occurred after the National Development and Reform Commission announced that it would raise the price of gasoline and diesel fuel from April 7. Since February, international oil prices have soared and are currently at a high level of more than US$100/bbl. This has driven up the price of the entire petrochemical product, raising concerns about rising production costs caused by rising energy prices, and increasing expectations for inflation. This has led to increased procurement efforts to drive up prices. Second, due to factors such as tight supply of natural gas or equipment itself, Sichuan Yulong, Shandong Luxi Chemicals and other major melamine plants have all been shut down for maintenance, resulting in a reduction in the supply of supplies; In addition, since the beginning of this year, the export situation of melamine in China has been very good. Many enterprises have export orders, and some companies even export. From January to February of this year, the total export volume was 32,600 tons, an increase of 97.58% from 16,500 tons in the same period of last year. The current FOB export price is between 1,520 and 1,550 U.S. dollars, which is equivalent to the domestic price.
1. According to the stress mode of the connection, there are common and reamed holes. The bolts used for reaming holes should match the size of the holes and be used when subjected to transverse force
2. According to the head shape, there are hexagon head, round head, square head, countersunk head and so on. Generally, countersunk head is used in the place where the surface is smooth and no protrusion is required after connection, because countersunk head can be screwed into parts. Round head can also be screwed into parts. The tightening force of square head can be larger, but the size is large. Hexagon head is the most commonly used.
In addition, in order to meet the needs of locking after installation, there are holes in the head and in the rod, which can prevent the bolts from loosening when they are subject to vibration.
Some bolts have no thread of smooth rod to do thin, called thin waist bolt. This kind of bolt is conducive to variable force connection.
There are special high strength bolts on the steel structure. The head will be bigger. The size will also change.
In addition, there are special uses: T-shaped slot bolts, most of which are used in machine tool fixtures, with special shape, and both sides of the head need to be cut off. Anchor bolts are used to connect the machine and the ground, and there are many shapes, such as U-shaped bolts, and so on.
There are also special studs for welding, one with thread and the other without thread, which can be welded on the parts, and the other side can directly screw the nut.