★ Product Material: All the nuts are made of premium brass, which has high hardness, no deformation, durable and reliable for long time use.★ Product Feature: The rugged hex nut has a strong resistance to tumbling, preventing the nuts from weakening and loosening under vibration and torque, enhance the locking force.★ Attention: These coarse nuts for coarse threaded bolts, be sure not to strip your nuts by over tightening. Please check the screw size carefully before purchasing.