2021年4月10日 · Property Class 8.8 bolts and screws have a minimum tensile strength of 800 MPa for bolts and screws 16mm in diameter and under, and 830 MPa for bolts and screws with a diameter over 16mm. To give you an idea of how this compares to the strength of inch-series fasteners, 6.9 MPa are about equal to 1 kpi. 800 MPa are about 155 ksi.

Grade 8 is one of the most commonly referenced high strength fasteners and falls under the SAE J429 Standard. It covers parts with threads from 1/4” thru to 1-1/2”. A354 Grade BD is also a commonly referenced high strength fastener standard with almost identical chemical and mechanical properties to the Grade 8.

在美国的标准中，紧固件的强度等级常用类别（Class）来表示，而不是Grade。 以下是美国标准中常见的几个类别及其代表的强度： Class 2：这是最常见的类别，代表普通商业级别的紧固件。

钢结构连接用螺栓性能等级分3.6、4.6、4.8、5.6、6.8、8.8、9.8、10.9、12.9等10余个等级，其中8.8级及以上螺栓材质为低碳合金钢或中碳钢并经热处理（淬火、回火），通称为 高强度螺栓 ，其余通称为普通螺栓。

These metric bolt torque charts show the ideal tightening torque for class 8.8, 10.9, and 12.9 bolts for both wet and dry tightening. The bolt’s class indicates its material strength, with higher numbers meaning higher tensile and yield strength.

The Class 8.8 standard includes Multiple national standards grades. We can provide various grades of steel plates, steel coils, steel bars, structural steels (including special-shaped parts) under the CEN/TS 13388 standard in various conventional sizes.

Navstar Steel is a leading manufacturer and supplier of the Grade 8.8 Bolts in different types. These are suitable for low tensile strength applications as the medium carbon material has low tensile strength. But the medium carbon content makes the Class 8.8 Nuts to …

Tensile Strength: The maximum load in tension (pulling apart) which a material can withstand before breaking or fracturing. Yield Strength: The maximum load at which a material exhibits a specific permanent deformation. Proof Load: An axial tensile load which the product must withstand without evidence of any permanent set.

2022年3月28日 · Among them, bolt grade 8.8 and above are made of low-carbon alloy steel or medium carbon steel and are generally called high-strength bolts after heat treatment (quenching and tempering), and the rest are generally called ordinary bolts.

螺栓中等级cl8.8是螺栓的性能等级的意思，cl是压力等级的缩写。 钢结构连接用螺栓性能等级分3.6、4.6、4.8、5.6、6.8、8.8、9.8、10.9、12.9等10余个等级，其中8.8级及以上螺栓材质为低碳合金钢或中碳钢并经热处理（淬火、回火），通称为高强度螺栓，其余通称为普通螺栓。 螺栓性能等级标号有两部分数字组成，分别表示螺栓材料的公称抗拉强度值和屈强比值。 3、螺栓材质的公称屈服强度达1000×0.9=900mpa级。 螺栓性能等级的含义是国际通用的标准，相同性能等级 …