F436 Washer
F436 washers are typically spring washers that are designed to provide a compressive force to fasteners, such as threaded fasteners, to maintain a tight fit and prevent loosening
F436 washers are typically made of spring steel and have a low spring rate to ensure they compress easily and provide a consistent compressive force on the fastener. They are commonly used in applications where a low spring rate is necessary, such as with lightweight fasteners or for extremely large or fastening gap dimensions.