The bolt has been around a long time. You don’t expect the design to change… I mean, it’s a bolt, right? Well, the Lock’n Bolt folks in Japan don’t seem to agree and Kenji Hasegawa, who runs Japanese automotive parts supply company Lock’n Bolt Corporation, is responsible for this invention, billing it as a one-piece bolt that technically requires no nut (though it’s still threaded for one, so that’s not entirely the purpose).
Hasegawa’s Lock’n Bolt-F is designed specifically for industrial and commercial applications where constant vibration can eventually loosen typical nut-and-bolt configurations. It’s the Lock’n Bolt. The Lock’n Bolt F-1 bolt has a through hole along its axis and features an inverted cone-shaped tip end with an embedded hex cap bolt that pulls the cone up, widening the end of the bolt and holding it fast within the material. The bottom end of the screw has two slits to expand the tip radially and secure it fast.
When you tighten down on the hex cap bolt, the end part of the screw is expanded radially and the screw thread of the bolt cut into that of the piece, which prevents loose.
The idea is that these bolts, once approved, could find their way onto civil and commercial projects of any type, including elevators, escalator, bridges, steel towers, and other construction jobs. One advantage of the Lock’n Bolt is that it prevents loosening up without any nut. As a result, the bolt would fit in particularly well as a rail fastener, rail car wheel fastener, engine fastener in airplanes and ships, engine fastener in busses and trucks, within construction machines, printing machines, and even high-stress devices like a roller coaster – anything used under vibrating circumstances.
- Lightweight (no nut)
- Enables locking on one side only
- Can be used repeatedly
- Can be fixed at the middle of the screw
- Locks securely
- Can be used for a through hole and a blind hole
- Equal tensile/shear/torque strength to a standard bolt
- Easily replaceable
There are currently several models of Lock’n Bolt, including the F-1 which we describe above, and the F-2 which is a surface-locking bolt that tightens the back end of the bolt against the back of the hole to force the separation of the split end. An F-3 and F-4 (countersunk head) are also available to fill in for more specific applications.