A fastening member includes a screw thread formed therein. A portion including a crest portion of the screw thread is formed of a first alloy material and includes: a thick portion where the portion is maximized in thickness in a circumferential direction; and a thin portion where the portion is minimized in thickness in the circumferential direction. A portion including a root of the screw thread is formed of a second alloy material having a tensile strength higher than that of the first alloy material.

An anchoring system for attaching equipment to a building foundation. The system includes an insert attached to the foundation by an adhesive, wherein the insert includes a flange that is positioned on a top surface of the foundation. The system also includes a washer element having a recessed portion for receiving the flange, wherein the washer also contacts the top surface. In addition, the system includes a rod element having a reference element, wherein the rod element is threadably engaged with the insert and the washer and wherein when the reference element is aligned with a reference plane indicative of level equipment, the washer is tightened against the top surface to preload the rod element to minimize deflection of the equipment.

An anchoring system for attaching equipment to a building foundation. The system includes an insert attached to the foundation by an adhesive, wherein the insert includes a flange that is positioned on a top surface of the foundation. The system also includes a washer element having a recessed portion for receiving the flange, wherein the washer also contacts the top surface. In addition, the system includes a rod element having a reference element, wherein the rod element is threadably engaged with the insert and the washer and wherein when the reference element is aligned with a reference plane indicative of level equipment, the washer is tightened against the top surface to preload the rod element to minimize deflection of the equipment.

A threaded installation is provided. The threaded installation includes a nut, a bolt, and a housing. The housing includes a threaded hole. A first threaded connection is formed where the bolt is threadably coupled with the nut, and a second threaded connection is formed where the bolt is threadably coupled with the threaded hole. The first threaded connection is characterized by a first flank angle, Θ.sub.2A, of threads of the bolt or threads of the nut. The second threaded connection is characterized by a second flank angle, Θ.sub.3B, of threads of the bolt or threads of the housing. The flank angles, Θ.sub.2A and Θ.sub.3B, satisfy the following equation: $k_2=\frac{\cos \left({\theta }_{2A}\right)}{\cos \left({\theta }_{3B}\right)}>1.00.$

A threaded installation is provided. The threaded installation includes a nut, a bolt, and a housing. The housing includes a threaded hole. A first threaded connection is formed where the bolt is threadably coupled with the nut, and a second threaded connection is formed where the bolt is threadably coupled with the threaded hole. The first threaded connection is characterized by a first flank angle, Θ.sub.2A, of threads of the bolt or threads of the nut. The second threaded connection is characterized by a second flank angle, Θ.sub.3B, of threads of the bolt or threads of the housing. The flank angles, Θ.sub.2A and Θ.sub.3B, satisfy the following equation: $k_2=\frac{\cos \left({\theta }_{2A}\right)}{\cos \left({\theta }_{3B}\right)}>1.00.$

[Problem] The purpose of the present invention is to provide an anti-loosening metallic male screw that can exhibit a sufficient anti-loosening effect by forming a flat part and a short slope in a part of the thread bottom of the male screw and thus ensuring pressure contact between a thread peak of a female screw and the slope at the thread bottom of the male screw. [Solution] An anti-loosening metallic male screw according to the present invention is to be engaged with a female screw for a metric screw, and is characterized in that the cross-sectional shape of the thread bottom of the metallic male screw is formed into a flat shape in which a non-pressurized flank side thereof is parallel to the axis of the male screw, is formed into a shape in which a pressurized flank side thereof is sloped toward the pressurized flank side with respect to an extension line of the flat part, and the outer diameter and the effective radial size of the metallic male screw are smaller than the reference sizes of the metric screw.

[Problem] The purpose of the present invention is to provide an anti-loosening metallic male screw that can exhibit a sufficient anti-loosening effect by forming a flat part and a short slope in a part of the thread bottom of the male screw and thus ensuring pressure contact between a thread peak of a female screw and the slope at the thread bottom of the male screw. [Solution] An anti-loosening metallic male screw according to the present invention is to be engaged with a female screw for a metric screw, and is characterized in that the cross-sectional shape of the thread bottom of the metallic male screw is formed into a flat shape in which a non-pressurized flank side thereof is parallel to the axis of the male screw, is formed into a shape in which a pressurized flank side thereof is sloped toward the pressurized flank side with respect to an extension line of the flat part, and the outer diameter and the effective radial size of the metallic male screw are smaller than the reference sizes of the metric screw.

An installation tool and fastener is particularly adapted for fastening a top plate to a roof support member and other structural connections. The installation tool comprises a telescopic tool assembly which transfers torque from a power driver tool to a fastener drive coupler. The installation tool has a receiver guide which is configured to concentrically guide a fastener into driver engagement with a fastener coupler. The coupler may have a driver tip with radial projections, a Philips driver tip or a square driver tip. In one embodiment, the installation tool fastener has a head with a maximum head diameter equal to the major thread diameter and a recess for coupling with the drive coupler.

An installation tool and fastener is particularly adapted for fastening a top plate to a roof support member and other structural connections. The installation tool comprises a telescopic tool assembly which transfers torque from a power driver tool to a fastener drive coupler. The installation tool has a receiver guide which is configured to concentrically guide a fastener into driver engagement with a fastener coupler. The coupler may have a driver tip with radial projections, a Philips driver tip or a square driver tip. In one embodiment, the installation tool fastener has a head with a maximum head diameter equal to the major thread diameter and a recess for coupling with the drive coupler.

An interlocking thread with a tooth-cross-section that is wider at its crest than at its root and with “V” angles located both along the crest and the root which tightens into a tapped hole that has a similar thread cross-section.