A metric self-tapping locking screw comprises a screw head which is connected to a thread locking body by a screw rod. The thread locking body and the self-tapping tip are provided with a screw thread on the surface. The self-tapping tip is arranged at the root of the thread locking body; the screw thread adopts the basic structure of the standard ordinary triangular thread. The flank angle back to the fastened surface is 15-20 and the flank angle of the screw thread facing the fastened surface is 30. The metric self-tapping locking screw in the Invention make the installed parts to be fastened have higher axial clamping force and static loosing moment, which solves the attenuation problem of axial clamping force and static moment of fastened parts.

An improved fastening device includes a shank portion with a first end and a second end disposed from the first end. The fastening device includes a head portion disposed adjacent the second end of the shank portion The head portion of the fastening device includes a lower perimeter adjacent the second end of the shank portion, an upper perimeter disposed away from the lower perimeter and a body portion extending between the lower perimeter and the upper perimeter. The head portion is configured to engage a standard hex-shaped socket. The lower perimeter of the head portion has a generally hex shape and the upper perimeter has a different shape than the lower perimeter.

An improved fastening device includes a shank portion with a first end and a second end disposed from the first end. The fastening device includes a head portion disposed adjacent the second end of the shank portion The head portion of the fastening device includes a lower perimeter adjacent the second end of the shank portion, an upper perimeter disposed away from the lower perimeter and a body portion extending between the lower perimeter and the upper perimeter. The head portion is configured to engage a standard hex-shaped socket. The lower perimeter of the head portion has a generally hex shape and the upper perimeter has a different shape than the lower perimeter.

A fastener with a body with a shank, a head adjacent one end of and integral with the shank, and a shoulder adjacent the head, and a separate washer with a through hole received on the shank, bearing on the shoulder and securely fastened to the shank. The body and washer may have an interference fit. The body may be made and the washer attached by cold forming the body with a ring bearing on the washer.

Various embodiments described herein provide a fastener system having straight walled driving surfaces that provides a reliable stick fit feature, while also improving stability of engagement between the system components. A feature of the new system is to allow stick fit engagement of existing standard straight walled drivers in the new system.

An improved fastening device includes a shank portion with a first end and a second end disposed from the first end. The fastening device includes a head portion disposed adjacent the second end of the shank portion The head portion of the fastening device includes a lower perimeter adjacent the second end of the shank portion, an upper perimeter disposed away from the lower perimeter and a body portion extending between the lower perimeter and the upper perimeter. The head portion is configured to engage a standard hex-shaped socket. The lower perimeter of the head portion has a generally hex shape and the upper perimeter has a different shape than the lower perimeter.

An improved fastening device includes a shank portion with a first end and a second end disposed from the first end. The fastening device includes a head portion disposed adjacent the second end of the shank portion The head portion of the fastening device includes a lower perimeter adjacent the second end of the shank portion, an upper perimeter disposed away from the lower perimeter and a body portion extending between the lower perimeter and the upper perimeter. The head portion is configured to engage a standard hex-shaped socket. The lower perimeter of the head portion has a generally hex shape and the upper perimeter has a different shape than the lower perimeter.

A compression indentation fastener device is described comprising a shank and a head. The head extends outwardly from an end of the shank in a transverse plane to define a head periphery. The head has an anterior side and a posterior side. The anterior side includes an exposed area extending between the shank and the head periphery. The anterior side includes a relief portion in the form of a depression. The relief portion is open at the anterior side of the head such that the relief portion receives a volume of substrate material when the exposed area of the head impacts the substrate material. The head may be integral with the shank or the head may be comprised of discrete head portions that mate with one another. Additionally, the head may be centered on the end of the shank or offset relative to the shank.

A compression indentation fastener device is described comprising a shank and a head. The head extends outwardly from an end of the shank in a transverse plane to define a head periphery. The head has an anterior side and a posterior side. The anterior side includes an exposed area extending between the shank and the head periphery. The anterior side includes a relief portion in the form of a depression. The relief portion is open at the anterior side of the head such that the relief portion receives a volume of substrate material when the exposed area of the head impacts the substrate material. The head may be integral with the shank or the head may be comprised of discrete head portions that mate with one another. Additionally, the head may be centered on the end of the shank or offset relative to the shank.

A mold, punch and workpiece are provided. In a preferred embodiment, a tapering outer edge is provided, along with a plurality of rib sets arranged circumferentially about the outer edge, and a ramp. A ramp may be located to facilitate the removal of burrs. Various slot patterns may be provided or formed, including star-shapes/Torx? slots. Using the present invention, a driver bit may be more securely fit to the slot of a screw, for example, allowing the screw to be threaded into a machined part more securely and smoothly, reducing rocking, shaking or tilt.