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How to judge the 10.9grade bolt

Time: 2018-07-30

To judge mechanical property of wheel bolt, we should from 3 parts that is hardness, tensile, and torque. These 3 items are indispensable. And the parameter of 10.9 grade bolts should have these parts: Rockwell hardness is HRC32-39, tension load≥73100N/㎜², tensile strength≥1040N/㎜².
Some factories say that their bolts are 10.9 grade just according to hardness test. It’s not rigorous and scientific. If they use wrong material and the hardness is too high, the products will be fragile and easy to break down. Bolts bear the weight of whole car, which is the safety part of car. The quality is very important.
“HONGSHENG” wheel bolt firstly choose good material. Then we will test hardness, tensile, and torque regularly everyday, and send samples to third-party test center to finish anti-fatigue testing to ensure every parameter is qualified then send to customs.