An aluminum alloy includes more than or equal to 1.0 mass% and less than or equal to 1.8 mass% of Si, more than or equal to 0.5 mass% and less than or equal to 1.2 mass% of Mg, more than or equal to 0.3 mass% and less than or equal to 0.8 mass% of Fe, more than or equal to 0.1 mass% and less than or equal to 0.4 mass% of Cu, more than or equal to 0.2 mass% and less than or equal to 0.5 mass% of Mn, more than or equal to 0 mass% and less than or equal to 0.3 mass% of Cr, at least one of more than or equal to 0.005 mass% and less than or equal to 0.6 mass% of Ni and more than or equal to 0.005 mass% and less than or equal to 0.6 mass% of Sn, Al, and an inevitable impurity.

A valve includes a set screw that is screwable into and out of a complementary female threaded opening in a valve part for changing a setting of the valve, for changing an adjustable flow restriction of the valve, in which the set screw includes a free outer end that projects outside the valve part, and a gripping part on its free outer end for a tool to be engageable thereupon. The free outer end of the set screw includes a male thread onto which a locking nut is screwed. A protective cap is provided for covering the free outer end, that includes a first cap portion with a rotation space for fitting freely rotatable over the locking nut, and a second cap portion with a complementary female thread that is screwed onto the male thread towards a locked position.

A concrete system comprising a concrete threaded rod and a concrete part having a threaded aperture for receiving the concrete threaded rod.

A concrete system comprising a concrete threaded rod and a concrete part having a threaded aperture for receiving the concrete threaded rod.

In implementations of a pressure lock retention fastener, the fastener assembly includes an insert sized for insertion into a fastener hole in a first panel. The fastener assembly has a threaded collet sized to slide in the insert and has expandable flanges that extend below the insert. The expandable flanges are sized for insertion into an aligned hole in a second panel. The fastener assembly also includes a screw installable through the insert to engage the threaded collet. The screw exerts a force that pushes the expandable flanges outward as screw rotation drives the screw into the threaded collet, and ridge locks of the expandable flanges seat up against the second panel effective to fasten the panels together. In implementations, a plate is installable between the panels with slotted holes having anti-rotation tabs that prevent a fastener assembly from spinning in the panel holes.

Disclosed is a sheet-metal fastener configured to join two components, such as sheet-metal. The sheet-metal fastener comprising a head and a shank. The head may define an undercut region and a serrated region. The serrated region can be positioned at an outer perimeter of the head. The serrated region can be composed of a plurality of knurls. The shank extends perpendicularly from the undercut region and comprises one or more threads.

Disclosed is a sheet-metal fastener configured to join two components, such as sheet-metal. The sheet-metal fastener comprising a head and a shank. The head may define an undercut region and a serrated region. The serrated region can be positioned at an outer perimeter of the head. The serrated region can be composed of a plurality of knurls. The shank extends perpendicularly from the undercut region and comprises one or more threads.

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 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 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.