SELF-BORING LOCK BOLT

PROBLEM TO BE SOLVED: To provide a self-boring lock bolt with excellent durability at low cost by using a welded steel pipe formed of a plated steel plate as a lock bolt body. SOLUTION: This self-boring lock bolt comprises: the hollow lock bolt body 1 having an injection hole 4 for grout, high-pressure air, and high-pressure water formed through the center part and a male screw 2 formed over the outer peripheral entire length; and a drilling bit 3 attached to the end of the bolt body and having an ejection hole 5 communicating with the injection hole 4. The hollow lock bolt body 1 is formed of a welded steel pipe by using, as a raw material, a coated steel plate on which a Zn plated layer, an Al-plated layer, a Zn-Al alloy plated layer, or a Zn-Al-Mg alloy plated layer is formed. The welded steel pipe is desirably one in which a plate correction layer is formed at or near a weld part on the outer surface of the pipe. COPYRIGHT: (C)2009,JPO&INPIT