Torque can be applied by "double-locking" the nuts and using a wrench to rotate the bolt rod. There's some fastening scenarios where plain locknuts don't fit the bill. This could be a delicate plastic housing or a vibration-prone setting. If the plastic housing is subjected to the full torque required of the work, then it could crack. A series of regular nuts and an equal amount of jam nuts pair up to remove strain from the housing.
The fragile object is properly supported, but no stress is directed at the plastic. In addition to this hypothetical application, double-locked fasteners promote finite adjustability, so rubber dampeners won't be overly compressed when a vibration heavy application crops up.
They may be thin, but jam nuts are the best solution when adjustability is required from a set of locknuts. Just remember to evenly torque each pairing so that every face drives uniformly into its companion. Copyright TCI Fasteners. Just placing two nuts on is not enough to hold heavy hex bolts in tightly. But with a heavy hex jam nut tightened just so and a standard heavy hex nut tightened on top, the locking mechanism will work and your fastener will be held tightly no matter what.
Started my career in the fastener world in at, Parker Kalon Corp. This was a successful adventure but ended in with me starting Melfast in August and have stayed competitive and successful to date. Melfast serves the OEM market with approximately accounts nationally. By Larry Melone. March 9th, by Larry Melone President. April 6th, by Larry Melone President.
The use of two plain nuts goes back at least years based upon observation of historic machinery. Tightening one nut down and then simply tightening another nut on top of it achieves little locking effect. A specific procedure needs to be followed if locking is to be achieved. When a thin and thick nut are used, it may be thought that the thick nut should go next to the joint since this would take the entire load.
However, by placing the thin nut on first, when the thick nut is tightened on top of it, the load on the threads of the thin nut are relieved of their load. The thin nut should be placed on the bolt first.
The second thick nut is then placed on the bolt and the thin nut held to prevent rotation by a spanner whilst the thick nut is tightened to the full torque value. The series of diagrams show the effect that the procedure has on forces present between the nuts and in the bolt. When the thick nut is tightened onto the thin nut, as the load increases, the load is lifted from the pressure flanks of the thin nut. As tightening continues a point is reached when the bolt thread touches the top flanks of the thin nut.
If tightening is continued, the force between the two nuts will continue to increase. If the thick nut is overtightened, there is the risk of thread stripping or the tensile fracture of the bolt between the two nuts. The reason why the two nut system is effective in resisting self loosening is due to the way the threads are jammed together hence the term jam nut being frequently used for the thin nut.
Since the bolt thread is in contact with the top flank of the small nut and the bottom flank of the top nut, relative thread movement is not possible. For self-loosening to occur, relative movement between the bolt and nut threads must occur. It is this jamming action that is the secret of the two-nut method. In order to achieve the appropriate bolt preload prior to the threads jamming it is necessary to tighten the smaller nut.
0コメント