SCREW

• Main Author: HADASE KATSUHIKO
• Format: Patent
• Language: English
• Published: 31.01.2002
• Edition: 7
• Subjects: BLASTING; BUILDING; DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS ORMACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS,CLIPS, WEDGES, JOINTS OR JOINTING; ENGINEERING ELEMENTS AND UNITS; FIXED CONSTRUCTIONS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; GUTTERS; HEATING; LIGHTING; MECHANICAL ENGINEERING; ROOF COVERINGS; ROOF-WORKING TOOLS; SKY-LIGHTS; THERMAL INSULATION IN GENERAL; WEAPONS

PROBLEM TO BE SOLVED: To provide a screw as a wood screw, for example, a screw used for fixing and holding a roof tile to a roof component. SOLUTION: In the screw having a pointed end on a tip of a shank and a head part on a tail end, the shank is successively constituted of at least a first shank part, a second shank part, and a third shank part which extend from the pointed end to the head part, a preceding thread part is formed on the first shank part, a reamer part is formed on the second shank part, and a succeeding thread part is formed on the third shank part. Inequalities D1>d1>R1 and D2>d1>R2 are satisfied, where D1 and R1 are the diameter at the ridge of thread and the diameter at the bottom of thread of the preceding thread part, respectively, d1 is the outside diameter of the reamer part, and D2 and R2 are the diameter at the ridge of thread and the diameter at the bottom of thread of the succeeding thread part, respectively.