Screws

摘要

A screw comprises an enlarged head; a large diameter screw rod having one end extending from the enlarged head; a small diameter screw rod having one end extending from another end of the large diameter screw rod; another end of the small diameter screw rod being formed as a tip end; a first thread extending from the large diameter screw rod and the small diameter screw rod; and the first thread extending to the tip end of the small diameter screw rod. A diameter of the first thread on the large diameter screw rod is large than that of the first thread on the small diameter screw rod. A pitch of the first thread on the large diameter screw rod is smaller than or equal to that of the first thread on the small diameter screw rod.

主权项

1. A screw comprising:
an enlarged head (10); a large diameter screw rod (1A) having one end extending from the enlarged head; a small diameter screw rod (1B) having one end extending from another end of the large diameter screw rod (1A); another end of the small diameter screw rod (1B) being formed as a tip end; a first thread (2) extending from the large diameter screw rod (1A) and the small diameter screw rod; and the first thread (2) extending to a tip end of the small diameter screw rod (1B); and wherein a diameter of the first thread (2) on the large diameter screw rod (1A) is larger than that of the first thread on the small diameter screw rod (1B); and wherein a pitch of the first thread (2) on the large diameter screw rod (1A) is smaller than that of the first thread (2) on the small diameter screw rod (1B).