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What is the corresponding table between the strength grade and material of bolts?
There is no absolute correspondence between bolt material and strength grade. First of all: the two are different concepts: the strength grade is commercial grade, while the material is special grade. Secondly: many kinds of materials can reach the same performance level through different processing techniques. In other words, the same material can also reach different performance levels through different processes. Commonly used correspondences: 4.8-----Q235 6.8-----35# 8.8----------35CrMoA 40Cr 45# 25Cr2MoVA 10.9 grade is mostly used in rigid structural bolts in the chemical industry. Most of the 12.9 grade is automotive standard parts. GB70 hexagon socket bolts are mostly 12.9 grade stainless steel. A2-50 60 70--------304 A4-60 70 80----316 Wait, I am a bolter.:victory:
See if this works? GB-T5783-2000 hexagon head bolt full thread http://bbs.hcbbs.com/viewthread.php?action=printable&tid=176568 This post was last edited by wisdom1010 on 2009-3-23 10:04 ]
The performance grades of bolts for structural connections are divided into more than 10 grades, including 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, and 12.9. The bolts of grade 8.8 and above are made of low-carbon alloy steel or medium-carbon steel and have been heat-treated (quenched and tempered). They are generally called high-strength bolts, and the others are generally called ordinary bolts. The bolt performance grade label consists of two parts of numbers, which represent the nominal tensile strength value and the yield strength ratio of the bolt material. For example, a bolt with performance level 4.6 means: 1. The bolt material has a nominal tensile strength of 400MPa. ； 2. The yield-strength ratio of the bolt material is 0.6 ； 3. The nominal yield strength of the bolt material reaches 400×0.6=240MPa. Performance level 10.9 high-strength bolts. After heat treatment, the material can reach 1. The nominal tensile strength of the bolt material reaches 1000MPa. ； 2. The yield-to-strength ratio of the bolt material is 0.9 ； 3. The nominal yield strength of the bolt material reaches 1000×0.9=900MPa level