| 摘要 |
A fastener comprises a first tapered portion (3) and a second tapered portion (5). Each of the tapered portions (3, 5) has a thicker end and a thinner end and the tapered portions (3, 5) are arranged so that the thicker portion of the first tapered portion (3) is adjacent the thicker portion of the second tapered portion (5). The angle of taper of the first tapered portion (3) is greater than the angle of taper of the second tapered portion (5). |
