Patent ID: 6450748
Filing Date: 2002-09-17
Classification: F16B

Abstract:
A screw comprising a shank portion, and a head portion and a tip portion on opposite ends of said shank portion, said shank portion having upper and lower shank parts and a continuous spiral screw thread that includes upper thread turns formed on said upper shank part and lower thread turns formed on said lower shank part, said screw thread having an upper thread surface, a lower thread surface, and a cutting line that interconnects said upper and lower thread surfaces at a radial edge of said upper and lower thread surfaces distal to said shank portion, each of said lower thread turns being formed with from three to six adjacent concave facets in succession along said cutting line, each of said concave facets having a radial width ranging from about 60 to 120 degrees such that adjacent concave facets in each of said lower thread turns cooperate to span the entire length of the respective one of said lower thread turns, each pair of said adjacent concave facets forming a pointed corner at said cutting line.