A multifunctional fastener is provided which is easy to install and combines a screw, and a washer and/or a wing assembly. The multifunctional fastener may include a fastener head. A threaded portion may extend longitudinally and distally of the fastener head. A fastener washer may be disposed between the fastener head and the threaded portion, and may extend radially outward of the fastener head. The wing assembly may include at least one fastener wing extending radially outward from the fastener head, and preferably radially outward of the fastener washer. A torque-applying tool connector may be provided in the fastener head. The torque-applying tool connector may be configured for engagement with a torque-applying tool such as a manual screwdriver or electric drill screwdriver to facilitate rotation of the threaded portion via the fastener head.

A precision adjustment fastener mechanism comprises a base, a platform, and a locking push-pull fastener assembly. The base has a first aperture and the platform has a second aperture. The fastener assembly is disposed within the second aperture. The fastener assembly comprises a clamping fastener having a portion positioned in the first aperture, a sleeve having a third aperture extending along an axis of the sleeve. The clamping fastener is positioned within the third aperture. The sleeve comprises a first portion moveable relative to a second portion along the axis. The first portion and the second portion each comprise outer threads. An axial displacement portion separates the first and second portions and transmits a torque between the first and second portions. The axial displacement portion facilitates movement of the first and second portions to bind threads of the first and second portions with the threads of the platform.

A precision adjustment fastener mechanism comprises a base, a platform, and a locking push-pull fastener assembly. The base has a first aperture and the platform has a second aperture. The fastener assembly is disposed within the second aperture. The fastener assembly comprises a clamping fastener having a portion positioned in the first aperture, a sleeve having a third aperture extending along an axis of the sleeve. The clamping fastener is positioned within the third aperture. The sleeve comprises a first portion moveable relative to a second portion along the axis. The first portion and the second portion each comprise outer threads. An axial displacement portion separates the first and second portions and transmits a torque between the first and second portions. The axial displacement portion facilitates movement of the first and second portions to bind threads of the first and second portions with the threads of the platform.

A fluid end having its fluid flow bores sealed without threading a retaining nut into the walls of each bore. The fluid ends may be assembled using a plurality of different kits, each kit comprising a fluid end body, a component, a retainer element, and a fastening system. The retainer element holds the component within each of the bores formed in the fluid end body and the fastening system secures the retainer element to the body. The fastening system comprises a plurality of externally threaded studs, washers and nuts in some embodiments. In other embodiments, the fastening system comprises a plurality of screws.

A fluid end having its fluid flow bores sealed without threading a retaining nut into the walls of each bore. The fluid ends may be assembled using a plurality of different kits, each kit comprising a fluid end body, a component, a retainer element, and a fastening system. The retainer element holds the component within each of the bores formed in the fluid end body and the fastening system secures the retainer element to the body. The fastening system comprises a plurality of externally threaded studs, washers and nuts in some embodiments. In other embodiments, the fastening system comprises a plurality of screws.

A bolted joint for coupling two components that undergo thermal expansion and contraction includes a bolt having a head and a stem, the bolt configured to provide a clamping force between the two components. A first washer having a thermal resistant, low friction coating is configured to be disposed between one of the two components and the bolt head to enable the one component to slide relative to the bolt during the thermal expansion and contraction, while maintaining the clamping force, to facilitate preventing bending or shearing of the bolt.

A bolted joint for coupling two components that undergo thermal expansion and contraction includes a bolt having a head and a stem, the bolt configured to provide a clamping force between the two components. A first washer having a thermal resistant, low friction coating is configured to be disposed between one of the two components and the bolt head to enable the one component to slide relative to the bolt during the thermal expansion and contraction, while maintaining the clamping force, to facilitate preventing bending or shearing of the bolt.

A variable flow rate valve mechanism includes a valve, a lock member, a valve attachment member and a spring washer. The valve includes a valve body and a valve shaft. The lock member is fixed to the valve shaft. The valve attachment member is attached to the valve shaft. The spring washer is disposed adjacent the valve attachment member. The spring washer is formed into an annular shape around an axis of the spring washer. The spring washer includes a support portion, a deformable portion and a protrusion portion. The support portion includes a seat surface and an open surface. The deformable portion is connected to the support portion and extends in an inclined manner. The deformable portion includes a contact surface and an opposite surface. The protrusion portion protrudes from at least one of the open surface of the support portion and the opposite surface of the deformable portion.

A variable flow rate valve mechanism includes a valve, a lock member, a valve attachment member and a spring washer. The valve includes a valve body and a valve shaft. The lock member is fixed to the valve shaft. The valve attachment member is attached to the valve shaft. The spring washer is disposed adjacent the valve attachment member. The spring washer is formed into an annular shape around an axis of the spring washer. The spring washer includes a support portion, a deformable portion and a protrusion portion. The support portion includes a seat surface and an open surface. The deformable portion is connected to the support portion and extends in an inclined manner. The deformable portion includes a contact surface and an opposite surface. The protrusion portion protrudes from at least one of the open surface of the support portion and the opposite surface of the deformable portion.

A bolt-nut (1) includes: a nut body (4) in a substantially cylindrical shape; plural nut divided bodies (4a); a cover body (5) in a substantially cylindrical shape for covering the nut body (4); a cover-side tapered portion formed on an inner wall of the cover body (5); a nut-side tapered portion (4a) formed such that an outer diameter of an outer wall of the nut body (4) is reduced toward one end portion thereof so as to correspond to the cover-side tapered portion; a spring (6) that is accommodated together with the nut body (4) in the cover body (5); and a nut (2) that includes a lid body (7) covering the other end portion of the cover body (5). A bolt screw as a ridge of the bolt and a nut screw as a ridge of the nut body (4) have unequal pitches that are different from each other.