High strength bolts, known as high strength bolt coupling pairs, are much stronger than normal bolts and are often used in large, permanent fixtures.Because the connection pair of high-strength bolts is special and has high technical requirements, it is necessary to deal with rain and moisture during transportation, especially to prevent damage to the thread of high-strength bolts, and to be lightly loaded and unloaded during handling.When high-strength bolts enter the site, they need to conduct entrance inspection, mainly for the torque coefficient inspection. The torque coefficient inspection of high-strength bolts is carried out on the torque coefficient tester, and the mean value and standard deviation of the torque coefficient are measured during the test.
The average torque coefficient of the high strength bolts is controlled at about 0.1 when the site acceptance, and the standard deviation is generally less than 0.1.Note that eight sets of bolts are used for the torque coefficient test, and each set of high-strength bolts cannot be reused. During the torque coefficient test, the pre-tension value of high-strength bolts should be controlled within the specified range. If the torque coefficient is beyond the specified range, the measured torque coefficient will be ineffective.The torque coefficient of the high strength bolt is guaranteed. After a certain period of time, the torque coefficient cannot be guaranteed to meet the pre-designed requirements. Generally, the guarantee period is six months.High strength bolts in the process of test make sure exert torque evenly, can not be shock, test environment should also be consistent with construction site, to be the same as the humidity, temperature used in the test apparatus and instrument and high strength bolt connection vice should be placed within this environment for at least two hours.
Post time: Sep-27-2019