... products include flange nut , hex nut and self-locking nut, the strength grades of them are 4 ... products include flange nut , hex nut and self-locking nut, the strength grades of them are 4 ... torsion bars each end is connected by self-lubricating joint bearings which is of low temperature ... simple structure, little weight, high strength, high self-vibration frequency, safety, long service life and so ...