As important hardware accessories for connecting and fixing various mechanical parts, screws are particularly common in our daily life and industrial production. According to their appearance, screws can be categorized into common machine screws, hexagonal screws, socket screws, self-tapping screws and expansion screws.
Common machine screws include slotted screws and cross-slotted screws. Slotted screws have a straight groove in the head, using a screwdriver to operate, commonly used in some simple wooden furniture assembly or connection of low precision requirements. Phillips slot screw head is a cross-shaped groove, the use of a cross screwdriver, compared to slotted screws, screwdriver and screw contact is more stable when tightening, not easy to slip off, widely used in a variety of mechanical equipment, electronic equipment shell fixed.
Hexagon socket head cap screws are hexagonal concave shape, need to use hexagonal wrench. Hexagon socket head cap screws can withstand greater torque, and after tightening the appearance of more simple and beautiful. Widely used in precision machinery, automotive manufacturing, aerospace and other fields, such as engine block connection, assembly of high-end instruments, etc., for the need for high reliability and high stability fastening occasions is the first choice.
Plum groove screws have a plum-shaped groove in the head, and a special plum wrench should be used. This screw has excellent anti-disassembly performance, suitable for high security requirements, such as public facilities in some key parts of the fixing, to prevent others from randomly disassembling the damage, but also for confidentiality needs of the equipment housing installation.
Self-tapping screws can be tapped directly on the material to be connected to the thread. Self-tapping screws have sharp threads, often used to connect thin metal, plastic and other materials. In the construction field to fix the light steel keel, in the electronic equipment to fix the thin plate shell and other scenes to play an important role, can improve the installation efficiency, without the need to connect the material in advance for complex tapping treatment.
Expansion screws are composed of screws, expansion tubes, nuts and so on. When the expansion screw is tapped into the hole and the nut is tightened, the expansion tube expands inside the hole and snaps tightly to the surrounding material. Commonly used for fixing objects on concrete, brick walls and other building structures, such as installing brackets for air conditioning outboard units, fixing various indoor hangings, pipe brackets, etc., they can provide a strong anchoring force to ensure the stability of the object being fixed.