Provided is a screw. A recess portion is formed at an end of the screw by extending a depth along a central axis direction of the screw. A tool matching structure is formed on a bottom surface of the recess portion for providing a tool that enters into the recess portion so as to make a part of the tool and the tool matching structure be matched to each other, thereby operating the tool to drive the screw for rotating.

Fasteners are disclosed for use with multiple standard torque delivery tools. The fasteners include several different torque bearing portions for use with different torque delivery tools, as well as non-torque bearing portions disposed between torque bearing portions.

A torque transmission driver has a first end portion adapted to receive and transmit torque from a torque generation source, and a second end portion including a shaped tapered bit having drive surfaces with an alternating series of five or six lobes and troughs about a rotational axis, having a taper angle between 15 and 65° from the rotational axis operable to engage corresponding drive surfaces in a plurality of at least two size fasteners, the tapered drive surfaces of the bit comprising a first tapered portion operable to engage drive surfaces of a first sized fastener and a second tapered portion operable to engage drive surfaces of a second sized fastener, the drive surfaces of the second sized fastener being larger than the drive surfaces of the first sized fastener. The taper angle may be nominally 52° from the rotational axis.

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.

A fastening system including a pin member and a key for engaging the pin member. The pin member includes a shank portion and a recess formed within an end face of the shank portion. The recess includes a plurality of splines and recesses that form first and second bearing surfaces oriented at angles. The key includes a key head having a plurality of splines and grooves that form first and second bearing surfaces oriented at angles. The plurality of splines and recesses of the pin member and the plurality of splines and recesses of the key are adapted to communicate with each other when tightening and loosening the pin member.

A T-Nut comprising a tubular body attached to a flanged head is provided. The tubular body includes a bottom portion of constant diameter and an upper neck portion with a neck diameter that gradually increases as it approaches the flange head. Additionally, the bottom surface of flange head of the T-Nut may be recessed inwardly towards the top surface of the flange head to create circumferential concave cavity underneath the flange head, which will allow the flange head to envelope any portions of a washer or casing that may be above the surface of the material being joined.

To provide a tensioning device capable of tensioning a bolt from a bolt head side while suppressing increase in the number of components. A tensioning device is configured to apply upward tension to a bolt fastened to a fastened member H. A first male thread portion is formed on an outer circumferential surface of a head of the bolt. The tensioning device includes a connection member having a first female thread portion to be threadly engaged with the first male thread portion, a tensioning mechanism for tensioning the bolt via the connection member in a state where the first male thread portion is threadly engaged with the first female thread portion, and a tension bearer which is disposed around an outer circumference of the connection member, and bears a reaction force applied from the fastened member H in tensioning performed by the tensioning mechanism.

A fastener including a first recess and a second recess adjacent the first recess. The first recess includes a side surface defining a shape of the first recess and a stability surface oriented at an angle of greater than 1 and less than or equal to 89 relative to a major axis of the fastener.

A drive system with full surface drive contact. The drive system tends to maximize the surface contact pattern or area at typical bit-recess reaction (drive) torque values, thereby tending to minimize bit-recess surface contact stresses, coating damage, recess ream and premature bit fatigue failure. The drive system comprises a fastener and/or bit having drive surfaces formed of either polygon involutes or a single arc construction. A punch is also provided for forming a recess in either the fastener or the bit, wherein the punch has corresponding surfaces.

A dental tool and prosthetic components/screws that allow capturing, transporting and applying torque so as to perform dental service with a single tool specially adapted for components/screws with reduced dimensions, such as, e.g., smaller than 1.4 mm in diameter.