Lag screw bolt with hexagonal head on one side and internal threads on both ends

Abstract

This product is a lag screw bolt with a hexagonal head on one side and internal threads on both ends that can reduce the load by responding to the tensile force applied to each tightening and fixing bolt itself so that the column and beam of the attached wooden material become integrally rigid when connecting beams or girders on both sides of a column in a wooden building using high-strength connecting hardware.The bolt has a thread shape like a lag screw with a high and large thread pitch and a shape where the threaded part bites into the wooden material, and the hexagonal head on one side and internal threads on both ends are first tightened before the bolt is tightened. The bolt is inserted into the wooden pillar and fixed, and then can be individually fitted with the tightening fixing bolt. The main body shape of the one-sided hexagonal head double-ended internally threaded lag screw bolt has a hexagonal head of a certain shape from one end, and the neck and threaded parts of the bolt are formed integrally in the opposite direction. It is characterized by the fact that the outer diameter of the neck is of a certain diameter and the outer diameter of the threaded part of the bolt are the same, the threaded part has high and large threads, and the thread pitch is also wide, so that when rotational force is applied, it bites into the wooden material and drives it forward while cutting the threads. The threaded portion extends to a fixed length, and the connecting hardware has an internal threaded portion that can be tightened with a high-strength hexagonal head bolt, and a mating female thread is cut to a fixed depth or length according to the diameter of the threaded portion of the high-strength hexagonal head bolt, as a common point on both ends, starting from the tip of the hexagonal head portion on one side of the one-side hexagonal head double-ended internally threaded lag screw bolt and the end of the lag screw-shaped thread on the other side. When attaching and fixing connecting hardware using a hexagonal head lag screw bolt, a pilot hole is drilled into the wooden material to be attached, with the diameter of the lag screw bolt's valley. The hexagonal head of the lag screw bolt with a hexagonal head on one side and internal threads on both ends is rotated and inserted using a jig and power tool, and first assembled and fixed to the pillar. After that, high-strength hexagonal head bolts are rotated and inserted into the internal female threads on both ends of the lag screw bolt with a hexagonal head on one side and internal threads on both ends through the fastening holes on the back of the connecting hardware, and then the bolts are fitted into the female threads and tightened to fix the connecting hardware.By being fixed in place without leaving a gap between the bolt pilot hole in the attached wooden material, the single-sided hexagonal head, double-ended internally threaded lag screw bolt and the wooden column function as a single unit and can withstand the tensile load generated in the tightening fixing bolt and the attached connecting hardware. This reduces the burden of tensile stress on each high-strength hexagonal head bolt when tightening the connecting hardware, maintaining the strength of the connecting hardware itself for a long period of time, and also prevents beam sagging due to rattles in the connecting hardware caused by vibrations during earthquakes, making it possible to maintain the strength of the building structure for a long period of time.

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