A part fastening structure fastens a part, using a bolt and a nut. The bolt includes a first spiral groove, a second spiral groove provided on a tip end side of the bolt with respect to the first spiral groove, a slit extending from a tip end of the bolt to the first spiral groove through the second spiral groove, and a loosening suppression groove extending from another end of the second spiral groove to the tip end side. The nut includes: a first nut member including a first pin protruding toward a central axis side and inserted into the first spiral groove; a second nut member including a second pin protruding toward the central axis side and inserted into the second spiral groove; and an urging member disposed between the first and second nut members and that urges the first nut member toward a head portion of the bolt.

A U-shaped clip for use in a driveline shield system having a cap disposed to releasably engage a bearing mounted adjacent a drive shaft. The cap supports a tubular guard or shield in a coaxial position relative to the drive shaft. One or more lugs on the bearing are disposed to seat in corresponding slots formed in the cap. When the lugs are seated in the slots, rotation of the cap relative to the bearing causes the bearing and the cap to engage one another. The U-shaped clip is pivotally mounted to the cap and rotatable between a first position in which the clip extends into the slot and secures the lugs in engagement with the cap and a second release position in which the clip is retracted from the slot, thereby permitting relative rotation between the cap and bearing.

A twist-lock button configured to securely fasten two articles together. Such a twist-lock button may have four pieces: a handle, a locking portion, a negative, and a button adapter. The negative attaches to an article by way of the button adapter. The locking portion attaches to the handle and passes through a button hole in the article to join with the negative by twisting 180 degrees, thereby fastening the two portions of the article together between the handle and the negative. This mechanism is more durable than hook and loop fasteners, more reliable than buttons and snaps, and less prone to jamming than zippers. In addition, the twist-lock button is easier to use for people with muscular or motor disabilities, such as cerebral palsy, ALS, stroke recoverees, and amputees.