Fasteners for composite material

摘要

A fastener (10) has a shaft (12), a head (14) at a first end of the shaft (12), and a point (16) at the other end of the shaft (12). A first portion (18) of the shaft (12) adjacent the point (16) is threaded. The first portion (18) typically extends about one-half the total length of the shaft (12). A second portion (20) of the shaft (12) adjacent the head (14) is not threaded, but has a plurality of spaced rings (22, 23, 25). A knurled portion (24) can be provided between the first and second portions (18, 20), if desired. Conventional symmetrical or asymmetrical thread can be used in the threaded portion (18), or a three lobe thread can be used. <IMAGE>