The number on the bolt refers to the strength level. For example, the number 4.8 means that the strength level of the bolt is 4.8, and its shear stress is 4.8 GPa. According to regulations, bolts with a strength grade of 8.8 or higher are collectively called high-strength bolts, and the rest are collectively called ordinary bolts. General bolts use "XY" to indicate the strength, X*100=the tensile strength of this bolt, X*100*(Y/10)=the yield strength of this bolt (because according to the label: yield strength/tensile strength =Y/10). For example, grade 4.8, the tensile strength of this bolt is 400MPa; the yield strength is 400*8/10=320MPa.
Bolts that are made of high-strength steel or require a larger pre-tightening force can be called high-strength bolts. High-strength bolts are mostly used for the connection of bridges, rails, high-pressure and ultra-high pressure equipment. The fracture of this kind of bolt is mostly brittle fracture. High-strength bolts applied to ultra-high pressure equipment need to be prestressed in order to ensure the tightness of the container.
Galvanizing ProcessOctober 25, 2023Today, the main focus is on the surface treatment galvanizing process of stainless steel products. The purpose of galvanization is to prevent corrosion on steel. Steel is susceptible to corrosion in t...view
China Packaging Federation Signed A Memorandum Of Strategic Cooperation With Alibaba Local LifeJuly 1, 2022On the afternoon of March 11, 2021, Han Xueshan, Vice President of China Baolian, met with Zheng Wei, Vice President of Alibaba Local Life, Tian Xiyan, General Manager of Cooperation and Development, ...view
The Versatility, Application, And Future Development of Steel DrumsNovember 10, 2023Steel drums, also known as 55-gallon drums, are widely used in various industrial applications due to their durability, versatility, and cost-effectiveness. In this article, we will explore some commo...viewRussia Is Considering Doubling The Export Tax On Scrap Steel To 90 Euros A Tonne.July 1, 2022Russia's economic development ministry is to decide the fate of the possible increase of ferrous scrap export duty to €90/tonne ($110) this week. This comes after economic development minister Ma...view
Why Is Winter Bad For Coating ConstructionJune 30, 20221. Storage and transportation problemsFor liquid coatings, there will be a melting point problem, northern China in November basically fell below the freezing point, it is obvious that in this case, w...view
Packaging Industry Outlook In ChinaJuly 1, 2022Since the informatization was taken as the key point of the development strategy of the manufacturing industry in 2015, the Chinese government has actively promoted the implementation of relevant poli...view
EN
ko 
fr 
de 
es 
it 
ru 
pt 
ar 
vi 
th 
