Method for fastening lag screw bolts to wooden members

Abstract

To provide a method for fastening lag screw bolts to wooden members that enables smooth threading of the lag screw bolts and reduces construction time. [Solution] A method for fastening a lag screw bolt 30, which has a threaded portion 10 and a body portion 20, to a wooden member 50, comprising a pre-drilling step of drilling a pre-drilled hole 52 in the wooden member 50, and a fastening step of fastening the lag screw bolt 30 by screwing it into the pre-drilled hole 52, wherein in the pre-drilling step the pre-drilled hole 52 the pre-drilled hole 52 is machined so that a first hole 53 corresponding to the threaded portion 10 has a hole diameter φ1 which is the same as or approximately the same as the root diameter and is continuous with a second hole 54 corresponding to the body portion 20 has a hole diameter φ2 which is the same as or approximately the same as the nominal diameter, and in the fastening step the lag screw bolt 30 is screwed into the pre-drilled hole 52 after applying a viscous fluid 70 to the tip 15 or near the tip of the threaded portion 10.

Description

Technical Field

[0001] The present invention relates to a method for fastening a lag screw bolt to a wooden member.

Background Art

[0002] In wooden buildings constructed by the wooden framing method, wooden members such as columns, beams, foundations, and wall materials, and various metal fittings may be fastened to each other via lag screw bolts. By applying lag screw bolts as the fastening means, the members can be firmly tightened together, the rigidity and shear strength of the joint between the members can be enhanced, and the seismic performance can be improved. Since the fastening by lag screw bolts is a mechanical fastening (joining), generally, an adhesive is not filled in the lower hole into which the lag screw bolt is threaded when fastening the lag screw bolt to a wooden member.

[0003] Since the lag screw bolt engages with the lower hole by being threaded therein, a lower hole having a hole diameter corresponding to the valley diameter, which is the diameter of the valley that is relatively smaller among the ridges and valleys forming the threaded portion of the lag screw bolt, is processed, and the lag screw bolt is threaded into this lower hole. Generally, the diameter of the ridge, which is larger than the valley diameter, is referred to as the nominal diameter with respect to the valley diameter.

[0004] On the other hand, there is also a GIR (Glued in Rod) joint in which a steel bar such as a deformed bar is inserted into a lower hole processed in a wooden member, various adhesives including an epoxy resin-based adhesive are filled into the lower hole, and the shear strength is developed by curing the adhesive. In the GIR joint, since it is necessary to spread the adhesive between the lower hole and the steel bar, generally, a lower hole having a larger diameter than the outer diameter of the steel bar is processed.

[0005] As described above, when fastening a lag screw bolt to a wooden member by machining a pilot hole with a diameter approximately equal to the valley diameter and screwing it into this pilot hole, if the wooden member is a relatively hard material such as Douglas fir, the frictional force between the lag screw bolt and the pilot hole becomes high. Even when using power tools such as a regular electric wrench, it is not possible to screw in the lag screw bolt smoothly, resulting in a time-consuming screwing process and, in some cases, causing the power tool to malfunction. Due to the high friction, the power tool generates heat, and before screwing in the next lag screw bolt into the pilot hole, it is necessary to wait for the heated power tool to cool down, which further increases the construction time when screwing in multiple lag screw bolts. In order to solve these problems, if the diameter of the pilot hole is made larger, as in a GIR joint, the engagement between the lag screw bolt and the pilot hole described above is eliminated, and the fastening strength expected from the lag screw bolt cannot be obtained.

[0006] Therefore, when fastening lag screw bolts to wooden members by screwing them into pre-drilled holes in the wooden members, a method is desired that enables smooth screwing of the lag screw bolts and shortens the construction time.

[0007] Here, Patent Document 1 proposes a method for screwing lag screws into wooden structural members, in which adhesive is injected into a tapped-out hole formed by a tap larger than the outer diameter of the lag screw bolt, and then the lag screw bolt is inserted. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 5830304 [Overview of the project] [Problems that the invention aims to solve]

[0009] The method for screwing lag screws described in Patent Document 1 involves injecting adhesive into a tapped, bottomed hole with a diameter larger than the nominal diameter of the lag screw bolt, and then inserting the lag screw bolt. This is not the usual method of screwing a lag screw bolt into a pilot hole with a diameter equivalent to both the root diameter and the bottom diameter, but rather corresponds to the GIR joint described above, and can be said to be merely applying a lag screw bolt to the steel rod to which it is applied. Therefore, it does not disclose a means to solve the above-mentioned problem, namely, the problem in the usual fastening method using lag screw bolts, in which a lag screw bolt is screwed into a pilot hole with a diameter equivalent to the root diameter.

[0010] The present invention has been made in view of the above problems, and aims to provide a method for fastening lag screw bolts to wooden members, which enables smooth screwing of the lag screw bolts into pre-drilled holes in the wooden members and shortens the construction time. [Means for solving the problem]

[0011] To achieve the above objective, one aspect of the method for fastening lag screw bolts to a wooden member according to the present invention is: A method for fastening a lag screw bolt to a wooden member, comprising a threaded portion and a body without threads, wherein the threaded portion has peaks and valleys, the diameter of the peaks being the nominal diameter and the diameter of the valleys being the valley diameter, The process of drilling pilot holes in wooden components, The process includes a fastening step of screwing the lag screw bolt into the pilot hole and fastening it, In the aforementioned pilot hole machining process, the pilot hole is machined so as to be continuous with a first hole having the same or approximately the same diameter as the root diameter and corresponding to the threaded portion, and a second hole having the same or approximately the same diameter as the nominal diameter and corresponding to the body portion. The fastening process is characterized by applying a viscous fluid to the tip or near the tip of the threaded portion, and then screwing the lag screw bolt into the pilot hole.

[0012] According to this embodiment, the present invention relates to a fastening method for fastening a lag screw bolt, which has a threaded portion and a body portion, to a wooden member. In this method, a first hole corresponding to the threaded portion has a hole diameter equivalent to the root diameter and is machined to be continuous with a second hole corresponding to the body portion has a hole diameter equivalent to the nominal diameter, and then a viscous fluid is applied to the tip or near the tip of the threaded portion. By screwing the lag screw bolt into the pilot hole with this fluid, the frictional force between the threaded portion and the hole wall of the first hole and the frictional force between the body portion and the hole wall of the second hole are reduced by the viscous fluid, enabling smooth screwing of the lag screw bolt and shortening the construction time.

[0013] Here, "the first hole has a diameter that is the same as or approximately the same as the valley diameter" means that the first hole has both the same diameter as the valley diameter and a diameter that is slightly different from the valley diameter, meaning that the first hole has a diameter equivalent to the valley diameter. This also applies to "the second hole has a diameter that is the same as or approximately the same as the nominal diameter," meaning that the second hole has a diameter equivalent to the nominal diameter. Furthermore, the wooden members to be fastened include various members such as wooden columns, beams, and walls.

[0014] Furthermore, another aspect of the method for fastening lag screw bolts to a wooden member according to the present invention is: A method for fastening a lag screw bolt to a wooden member, wherein the lag screw bolt has threads with peaks and valleys, the diameter of the peaks being the nominal diameter, and the diameter of the valleys being the valley diameter, The process of drilling pilot holes in wooden components, The process includes a fastening step of screwing the lag screw bolt into the pilot hole and fastening it, In the aforementioned pilot hole machining process, the pilot hole is machined to have a hole diameter that is the same as or approximately the same as the valley diameter. The fastening process is characterized by applying a viscous fluid to the tip or near the tip of the threaded portion, and then screwing the lag screw bolt into the pilot hole.

[0015] According to this embodiment, the method for fastening a lag screw bolt, which has only a threaded portion and no body, to a wooden member is as follows: After machining a pilot hole with a hole diameter equivalent to the root diameter, a viscous fluid is applied to the tip or near the tip of the threaded portion, and the lag screw bolt is then screwed into the pilot hole. This reduces the frictional force between the threaded portion and the hole wall of the pilot hole, enabling smooth screwing of the lag screw bolt and shortening the construction time.

[0016] Furthermore, another aspect of the method for fastening lag screw bolts to a wooden member according to the present invention is: The viscous fluid is characterized by being one of the following: an adhesive, a sealant, or a grease.

[0017] According to this embodiment, by using a viscous fluid that is one of an adhesive, a sealant, or a grease, the frictional force between the lag screw bolt and the hole wall of the pilot hole can be effectively reduced.

[0018] In this case, if the viscous fluid is an adhesive, its adhesive effect can eliminate the return torque after the lag screw bolt has been screwed into the pilot hole and fastened, resulting in a higher torque compared to the torque at the time of fastening. This has been demonstrated to shorten construction time and increase fastening strength.

[0019] Furthermore, another aspect of the method for fastening lag screw bolts to a wooden member according to the present invention is: The characteristic feature is that the amount of viscous fluid adhering to the surface is 1 g to 3 g.

[0020] According to this aspect, by applying a viscous fluid of 1 g to 3 g to the generally applied lag screw bolts of M12 or M16 size, smooth screwing of the lag screw bolts can be achieved while suppressing the overflow of the viscous fluid from the lower hole.

[0021] Further, another aspect of the method for fastening a lag screw bolt to a wood member according to the present invention is the lag screw bolt includes a head at an end of a body portion or an end of a threaded portion, in the fastening step, the head is fitted into the power tool so as not to be relatively rotatable, and the power tool is driven to screw the lag screw bolt into the lower hole.

[0022] According to this aspect, when screwing the lag screw bolt using a power tool, the frictional force between the lag screw bolt and the hole wall of the lower hole is reduced, so that it is possible to suppress the power tool from generating heat during screwing, and it is not necessary to wait for the heat to cool down and then construct the next lag screw bolt. Therefore, the fastening construction of a plurality of lag screw bolts can be continuously performed.

Effect of the Invention

[0023] As can be understood from the above description, according to the method for fastening a lag screw bolt to a wood member of the present invention, when screwing and fastening the lag screw bolt to the lower hole processed in the wood member, smooth screwing of the lag screw bolt can be achieved and the construction time can be shortened.

Brief Description of the Drawings

[0024] [Figure 1A] It is a process diagram of an example of the method for fastening a lag screw bolt to a wood member according to the first embodiment. [Figure 1B] Following FIG. 1A, it is a process diagram of an example of the fastening method according to the first embodiment. [Figure 1C] Following FIG. 1B, it is a process diagram of an example of the fastening method according to the first embodiment. [Figure 1D] Following Figure 1C is a process diagram of an example of the fastening method according to the first embodiment. [Figure 2A] This is a process diagram of an example of a method for fastening lag screw bolts to a wooden member according to the second embodiment. [Figure 2B] Following Figure 2A, this is a process diagram of an example of a fastening method according to the second embodiment. [Figure 2C] Following Figure 2B is a process diagram of an example of a fastening method according to the second embodiment. [Figure 2D] Following Figure 2C is a process diagram of an example of a fastening method according to the second embodiment. [Figure 3] This figure shows the experimental results verifying the construction time and return torque. [Modes for carrying out the invention]

[0025] Hereinafter, an example of a method for fastening lag screw bolts to wooden members according to each embodiment will be described with reference to the attached drawings. In this specification and drawings, substantially identical components may be denoted by the same reference numerals to avoid redundant explanations.

[0026] [Method for fastening lag screw bolts to a wooden member according to the first embodiment] First, an example of a method for fastening lag screw bolts to a wooden member according to the first embodiment will be described with reference to Figures 1A to 1D. Here, Figures 1A to 1D are, in order, process diagrams of an example of a method for fastening lag screw bolts to a wooden member according to the first embodiment.

[0027] First, as shown in Figure 1A, a pilot hole 52 is drilled from the surface 51 of the wooden member 50 to an intermediate position inside it. Here, the wooden member 50 includes various members such as wooden columns, beams, and walls, and the target wood species for construction include various types of wood such as Japanese red pine, Japanese larch, Douglas fir, Japanese cedar, Japanese cypress, and Japanese cedar.

[0028] Using two types of drills or awls of different diameters, a second hole 54 with a relatively larger diameter of φ2 is machined on the surface 51 side of the wooden member 50. Then, while aligning the axis with the second hole 54, a first hole 53 with a relatively smaller diameter of φ1 is machined so as to be continuous with the second hole 54, thereby machining a pilot hole 52 in which the first hole 53 and the second hole 54 are continuous (this is the pilot hole machining process).

[0029] A lag screw bolt 30, which has a threaded portion 10 and a body portion 20, and a head portion 25 at the end of the body portion 20, will be screwed into the pilot hole 52.

[0030] The threaded portion 10 has peaks and valleys, and the valley diameter is φ1. That is, the first hole 53 is machined to have a hole diameter equivalent to the valley diameter of the threaded portion 10.

[0031] On the other hand, the diameter of the body portion 20 is the nominal diameter φ2, which is the diameter of the threads of the screw portion 10. That is, the second hole 54 is machined to have a hole diameter corresponding to the nominal diameter of the body portion 20.

[0032] The head 25 at the end of the body 20 of the lag screw bolt 30 is designed to accommodate an electric power tool (not shown) in a way that prevents relative rotation.

[0033] After drilling pilot holes 52 in the wooden member 50, as shown in Figure 1B, a metal plate 60 having a third hole 62 with a hole diameter approximately the same as the diameter φ2 of the second hole 54 is installed at a position corresponding to the pilot holes 52 on the surface 51 of the wooden member 50.

[0034] Here, the metal plate 60 is an example of a connecting fitting for the wooden member 50. Although the illustrated example is shown in a plate shape, it may be a connecting fitting of various shapes, such as U-shaped or L-shaped. Alternatively, another wooden member having a third hole may be installed instead of the metal plate 60.

[0035] When screwing the lag screw bolt 30 into the third hole 62 of the metal plate 60 and the pilot hole 52 of the wooden member 50, adhesive 70 (viscous fluid) is applied near the tip 15 of the threaded portion 10.

[0036] The adhesive 70 used here can be of various types, such as urethane, epoxy, or acrylic. For example, it is preferable to select the type of adhesive according to the purpose, such as using an acrylic adhesive if you want to speed up the curing process, or using an epoxy adhesive if you want to obtain high adhesive strength. In particular, it is preferable to use a urethane adhesive that hardens by absorbing the small amount of moisture contained inside the wood component 50, as this allows for the achievement of appropriate adhesive strength while keeping material costs as low as possible.

[0037] Furthermore, the viscous fluid adhering to the vicinity of the tip 15 of the screw portion 10 may be a sealant or grease instead of an adhesive. While sealants and greases cannot be expected to provide the same effect as adhesives in obtaining a higher torque compared to the torque during fastening, they can shorten the construction time in a similar way to adhesives.

[0038] The lag screw bolts 30 that are screwed into the pilot hole 52 can be of M12 or M16 size. When using lag screw bolts of these sizes, the amount of adhesive 70 that adheres near the tip 15 of the threaded portion 10 is adjusted to approximately 0.5g to 3g. As explained below, by applying adhesive 70 in this range (strictly speaking, 1g to 3g in the experiment), it has been demonstrated that the construction time can be significantly reduced and a higher torque can be obtained compared to the torque used during fastening.

[0039] After applying adhesive 70 near the tip 15 of the threaded portion 10, as shown in Figure 1C, a power tool (not shown) is fitted onto the head 25 of the lag screw bolt 30, the threaded portion 10 is inserted through the third hole 62 of the metal plate 60, and the power tool is driven to rotate the lag screw bolt 30 in the X1 direction while screwing it into the pilot hole 52 of the wooden member 50 in the X2 direction.

[0040] When the threaded portion 10 is screwed into the pilot hole 52 with adhesive 70 attached near the tip 15 of the threaded portion 10, the adhesive 70 attached near the tip 15 of the threaded portion 10 moves towards the back of the pilot hole in the X2 direction as the threaded portion 10 is screwed in, but remains in the middle of the first hole 53 and the second hole 54, and a portion of it flows back towards the hole opening in the X3 direction.

[0041] As the other areas of the screw portion 10 (areas other than the tip) move towards the back of the pilot hole 52, they come into contact with the adhesive 70 located midway through the pilot hole 52. This causes the entire screw portion 10 to come into contact with the adhesive 70, thereby reducing the frictional force between the entire screw portion 10 and the wall of the first hole 53.

[0042] Subsequently, the body portion 20, which moves following the screw portion 10, also comes into contact with the adhesive 70 that remains in the middle of the pilot hole 52, thereby reducing the frictional force between the body portion 20 and the hole wall of the second hole 54.

[0043] As shown in Figure 1D, the lag screw bolt 30 is screwed in, and its head 25 engages with the surface 61 of the metal plate 60, thereby fastening the lag screw bolt 30 to the wooden member 50 (this concludes the fastening process).

[0044] According to the fastening method shown in the illustration, in a method of fastening a lag screw bolt 30 having a threaded portion 10 and a body portion 20 to a wooden member 50, a pilot hole 52 is machined so that a first hole 53 corresponding to the threaded portion 10 has a hole diameter φ1 corresponding to the root diameter and a second hole 54 corresponding to the body portion 20 has a hole diameter φ2 corresponding to the nominal diameter and is continuous with the first hole 52. Then, with a viscous fluid 70 attached to the tip or near the tip 15 of the threaded portion 10, the lag screw bolt 30 is screwed into the pilot hole 52. This reduces the frictional force between the threaded portion 10 and the hole wall of the first hole 53 and the frictional force between the body portion 20 and the hole wall of the second hole 54, enabling smooth screwing of the lag screw bolt 30 and shortening the construction time.

[0045] Furthermore, by applying an adhesive to the viscous fluid 70, the adhesive effect eliminates the return torque after the lag screw bolt 30 is screwed into the pilot hole 52 and fastened, resulting in a higher torque compared to the torque at the time of fastening. This not only shortens the construction time but also increases the fastening strength.

[0046] [Method for fastening lag screw bolts to a wooden member according to the second embodiment] Next, with reference to Figures 2A to 2D, an example of a method for fastening lag screw bolts to a wooden member according to the second embodiment will be described. Here, Figures 2A to 2D are, in order, process diagrams of an example of a method for fastening lag screw bolts to a wooden member according to the second embodiment.

[0047] The fastening method shown in the illustrated example differs from the fastening method according to the first embodiment in that the lag screw bolt 30A used is a fully threaded type lag screw bolt that has only a threaded portion 10A and no body, and in order to screw this type of lag screw bolt 30A into the wooden member 50, a pilot hole 55 is machined with a hole diameter φ1 corresponding to the root diameter and with a uniform cross-section throughout.

[0048] As shown in Figure 2A, a pilot hole 55 is drilled in the wooden member 50 (pilot hole drilling process), and then, as shown in Figure 2B, a metal plate 60A having a third hole 63 with a hole diameter of φ1 is installed on the surface 51 of the wooden member 50.

[0049] Adhesive 70 is applied near the tip 15 of the threaded portion 10A of the lag screw bolt 30A. As shown in Figure 2C, the threaded portion 10A is inserted into the pilot hole 55 through the third hole 63, and the lag screw bolt 30A is screwed into the pilot hole 55 towards the back side in the X2 direction while rotating it in the X1 direction.

[0050] As shown in Figure 2D, the lag screw bolt 30A is screwed in, and its head 18 engages with the surface 61 of the metal plate 60A, thereby fastening the lag screw bolt 30A to the wooden member 50 (this concludes the fastening process).

[0051] Even with the fastening method shown in the illustration, the frictional force between the threaded portion 10A and the hole wall of the pilot hole 55 is reduced by the viscous fluid 70, enabling smooth threading of the lag screw bolt 30A and shortening the construction time.

[0052] Furthermore, by applying an adhesive to the viscous fluid 70, the adhesive effect eliminates the return torque after the lag screw bolt 30A is screwed into the pilot hole 55 and fastened, resulting in a higher torque compared to the torque at the time of fastening. This not only shortens the construction time but also increases the fastening strength.

[0053] [Experiments and results verifying construction time and return torque] Next, referring to Figure 3, we will explain the experiment conducted by the inventors to verify the construction time and return torque, and the results thereof.

[0054] The wood material used in the experiment was Douglas fir, weighing 6.0 kg with a specific gravity of 0.496. The pilot holes drilled in the wood material were as follows: the second hole had a diameter of φ12 mm and a depth of 50 mm, while the first hole had a diameter of φ9 mm and a depth of 110 mm. The lag screw bolts used were M12 in size and 125 mm in length. The adhesive used was Konishi Bond Co., Ltd., product name: KU928CV-2way pack (nozzle diameter 5 mm).

[0055] In the experiment, two types of power tools (impact drivers) with voltages of 18V and 14.4V were used, and the amount of adhesive applied was set to 1g and 3g for each example. In contrast, a standard fastening method using lag screw bolts without adhesive was used as a comparative example. The experimental overview and results are shown in Figure 3.

[0056] As shown in Figure 3, in comparative examples 1-3 using an 18V power tool without adhesive, the average construction time was 21.15 seconds, and while the average initial torque was 13.7 N·m, the average return torque decreased to 9.8 N·m.

[0057] In contrast, in Examples 2-4 (Example 1 was excluded because the adhesive splattered), where 3g of adhesive was applied near the tip of the lag screw bolt using an 18V power tool before screwing it in, the average installation time was 7.25 seconds, demonstrating that the installation time was reduced by approximately three times compared to the average of the comparative examples.

[0058] Furthermore, in Examples 2-4, while the initial average torque was 10.0 N·m, the return torque, contrary to the decrease (not the return torque itself), was demonstrated to increase 6.5 times to 64.8 N·m.

[0059] These results are due to the fact that applying adhesive near the tip of the threaded portion of the lag screw bolt before screwing it into the pilot hole reduces friction, making screwing smoother and significantly shortening installation time. Furthermore, the adhesive effect of the hardened adhesive prevents torque from returning, and in fact significantly increases the fastening strength of the lag screw bolt.

[0060] Furthermore, in Examples 5-7, where the amount of adhesive applied was 1g, it was demonstrated that the construction time could be reduced to the same extent as when 3g of adhesive was applied. On the other hand, regarding the return torque, although the torque was reduced compared to Examples 2-4 due to the reduced amount of adhesive applied, the torque increased by approximately 3.9 times compared to the initial torque, indicating that the fastening strength of the lag screw bolt was significantly increased due to the adhesive effect of the hardened adhesive.

[0061] Furthermore, in the comparison between Comparative Example 4 and Examples 8 and 9, where a 14.4V power tool was used, a significant reduction in construction time was demonstrated, and similar effects were demonstrated, such as a substantial increase in the fastening strength of the lag screw bolts due to the increase in torque.

[0062] In summary, this experiment demonstrates the significant reduction in construction time achieved by applying a viscous fluid when screwing lag screw bolts into pre-drilled holes, and the significant increase in fastening strength achieved by applying an adhesive to the viscous fluid.

[0063] Furthermore, other embodiments may be used in which other components are combined with the configurations listed in the above embodiments, and the present invention is not limited in any way to the configurations shown herein. In this regard, modifications can be made without departing from the spirit of the present invention, and can be appropriately determined according to the application form. [Explanation of Symbols]

[0064] 10,10A: Screw part 15: Tip 18:Head 20: Torso 25:Head 30,30A: Lag screw bolt 50: Wood-based components 51: Surface 52: Pilot hole 53: 1st hole 54:Second hole 55: Pilot hole 60, 60A: Metal plate 61: Surface 62,63:3rd hole 70: Viscous fluid (adhesive)

Claims

1. A method for fastening a lag screw bolt to a wooden member, comprising a threaded portion and a body without threads, wherein the threaded portion has peaks and valleys, the diameter of the peaks being the nominal diameter and the diameter of the valleys being the valley diameter, The process of drilling pilot holes in wooden components, The process includes a fastening step of screwing the lag screw bolt into the pilot hole and fastening it, In the aforementioned pilot hole machining process, the pilot hole is machined such that a first hole having the same or approximately the same diameter as the root diameter and corresponding to the threaded portion is continuous with a second hole having the same or approximately the same diameter as the nominal diameter and corresponding to the body portion. A method for fastening a lag screw bolt to a wooden member, characterized in that, in the fastening step, a viscous fluid is applied to the tip or near the tip of the threaded portion, and then the lag screw bolt is screwed into the pilot hole.

2. A method for fastening a lag screw bolt to a wooden member, wherein the lag screw bolt has threads with peaks and valleys, the diameter of the peaks being the nominal diameter, and the diameter of the valleys being the valley diameter, The process of drilling pilot holes in wooden components, The process includes a fastening step of screwing the lag screw bolt into the pilot hole and fastening it, In the aforementioned pilot hole machining process, the pilot hole is machined to have a hole diameter that is the same as or approximately the same as the valley diameter. A method for fastening a lag screw bolt to a wooden member, characterized in that, in the fastening step, a viscous fluid is applied to the tip or near the tip of the threaded portion, and then the lag screw bolt is screwed into the pilot hole.

3. The method for fastening a lag screw bolt to a wooden member according to claim 1 or 2, characterized in that the viscous fluid is one of an adhesive, a sealant, or a grease.

4. The method for fastening a lag screw bolt to a wooden member according to claim 1 or 2, characterized in that the amount of viscous fluid adhering to it is 1 g to 3 g.

5. The lag screw bolt has a head at the end of the body or the end of the threaded portion, A method for fastening a lag screw bolt to a wooden member according to claim 1 or 2, characterized in that, in the fastening step, the head is fitted to the power tool so as not to rotate relative to it, and the power tool is driven to screw the lag screw bolt into the pilot hole.

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