4 holes adjustable torque metal hinge: It is divided into ordinary type and bearing type, the ordinary type has been mentioned before. Bearing type can be divided into copper and stainless steel. Judging from the current consumption situation, copper bearing hinges are more often used because they are beautiful, beautiful, affordable, and equipped with screws. This metal hinge is one of the most popular products in the industry hinge. https://www.kasna-hardware.com/i...-torque-metal-hinge.html