A foreign material exclusion plug is disclosed. The foreign material plug includes a cylindrical body, a slot, and a breakaway tab. The cylindrical body includes an externally-threaded cylindrical structure. The slot is formed in the cylindrical body extending into the cylindrical body from a top surface of the cylindrical body. The breakaway tab is connected to the cylindrical body and extends outwards from the top surface.

A foreign material exclusion plug is disclosed. The foreign material plug includes a cylindrical body, a slot, and a breakaway tab. The cylindrical body includes an externally-threaded cylindrical structure. The slot is formed in the cylindrical body extending into the cylindrical body from a top surface of the cylindrical body. The breakaway tab is connected to the cylindrical body and extends outwards from the top surface.

An apparatus including a lower end fitting having a top planar surface, a bottom planar surface, a counterbore defined therebetween, an opening extending from the counterbore to the top planar surface, and a lock recess that extends both radially outwardly from the counterbore and extends inwardly into the lower end fitting from the bottom planar surface. The apparatus includes a guide tube having a lower end and an end plug configured to connect with the lower end of the guide tube. The end plug has a threaded shaft sized to pass through the opening of the lower end fitting, and a female lock nut has a deformable side wall configured to be swaged into the recess of the lower end fitting. The lock recess remains visible as viewed from the bottom planar surface of the lower end fitting when the female lock nut is fully disposed in the counterbore.

A fastener including a shank extending in a direction along a major axis; and a head comprising a hexalobular recess, wherein the hexalobular recess has an inner lobe surface having a radius satisfying

0.234A≤R.sub.i≤2.165A,

wherein A is an outer diameter of the hexalobular recess, and R.sub.i is the radius of the inner lobe surface.

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.

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.

A self-drilling ground screw for electrical grounding. The self-drilling ground screw includes a shaft having a proximal end and a distal end, wherein a head is affixed to the proximal end. The shaft further includes a threaded portion and a drill bit portion thereon, wherein threading is disposed about the shaft along the threaded portion. The drill bit portion includes spiral cutting edges therealong. A protrusion extends from the distal end, wherein the protrusion tapers to a point.

A rotary fastening device includes a rotating axial member and an inertia member. The rotating axial member includes a base body, an input end, an output end and an engaging portion. The input end is disposed at one end of the base body and selectively connected to a wrench. The output end is disposed at the other end of the base body. The engaging portion is disposed on the base body. The inertia member is detachably connected to the rotating axial member, and includes a gravity portion and an engaging hole. The gravity portion is extended toward the output end of the rotating axial member so as to form an annular space. The engaging hole is communicated to the annular space.

A fastener system includes a bolt and a retainer. The bolt has a first end and an opposing second end, wherein a recess having a predetermined shape is defined in the first end of the bolt. The retainer includes a first end having a predetermined shape configured to be inserted within the recess in the first end of the bolt and a second end configured to couple about the second end of the bolt. A method of fastening parts together with the fastener system includes inserting the first end of the retainer into the recess of the bolt, deflecting and/or rotating the retainer in a direction to bring the second end of the retainer into proximity with the second end of the bolt, and securing a nut to the bolt.

A threaded fastener includes a head end, a shank and an entry end, the head end located at one end of the shank and the entry end located at an opposite end of the shank. The head end includes an end face with a drive recess configured for being driven by multiple drive bit shapes, including a star or six lobe drive, a Phillips drive, a square drive and a flat blade drive.