Hex head SEMS screws with spring washers are a type of fastener commonly used in various industries and applications. They are designed to provide secure and reliable fastening while also offering the added benefit of built-in spring washers.

The term "SEMS" stands for "Screw and External Tooth Lock Washer" or "Screw and Split Lock Washer." SEMS screws are essentially pre-assembled fasteners that consist of a screw and a washer permanently attached to it. In the case of hex head SEMS screws, the screw has a hexagonal head, allowing for easy installation using a wrench or socket.

The spring washer, also known as a lock washer, is a small, circular washer with a split or serrated edge. Its purpose is to provide tension and prevent the screw from loosening due to vibrations or other external forces. The spring action of the washer creates a constant pressure against the screw and the surface it is fastened to, ensuring a secure joint.

Hex head SEMS screws with spring washers offer several advantages. They simplify the assembly process by eliminating the need to manually handle and position separate washers. This saves time and reduces the risk of misalignment or misplacement. The integrated spring washer enhances the screw's resistance to loosening, making it ideal for applications where vibration or movement is a concern.

These screws are available in various sizes, materials, and finishes to suit different requirements. Common materials include stainless steel, carbon steel, and alloy steel, each offering specific characteristics such as corrosion resistance or high tensile strength.

Hex head SEMS screws with spring washers are versatile fasteners that provide both secure fastening and resistance to loosening. Their pre-assembled design simplifies installation, making them a popular choice in many industries.