About “L/R Neji”

Perfect controll of looseness.

 By screwing the left-hand thread nut and the right-hand thread nut onto the “L/R Bolt” that is screwable and has a special three-dimensional structure but is non-spiral, these nuts are mechanically connected. This “L/R Neji” is a "Screw that does not loosen" with an innovatively different fastening method, that does not depend on the friction welding force which is the conventional screw locking principle.

The Challenge of Redefining

 Our aim is “To provide a continuous high level of safety and security through our important security products backed by our technical capabilities of the whole company’s collective efforts, while spreading them all over the world.” Based on this intent, NejiLaw was established in 2009 as a manufacturer of high-performance and advanced joining technology with “L/R Neji” as its main product.
Screws have a history of over 2000 years. The basic functions of the screw structure include the movements of objects and power transmissions. In addition, screws have the function of fastening and joining things.
The application of screw fastening body is firmly established as the most widely used mechanical element of industrial products to this day. This screw fastening body, that is, screws are naturally required not to be loosened.
 However, conventional screws carry the fate of being loosened inevitably due to their spiral structure.
Therefore, NejiLaw decided to re-examine the conventional spiral structure itself that depends on the frictional force between the screw threads of the conventional male screw and female screw. Since the first invention of the screw fastening body that broke the spiral structure principle, we have repeated many years of trial and error, invention after invention and research after research. The development was extremely difficult. At that time, there wasn't even a lathe in the apartment so called “Laboratory”. The difficulties continued. Although we finally were able to load the lathe and start the turning process, the L/R Neji made by the lathe had the blade scraped off and the screw threads just fell apart. It was far from a dream come true to create the shape we wanted. However, if you give up, the dream ends there. No one on the development team gave up.
After carefully overcoming the challenges that emerged one after another, the team finally got to one finished and completed form. It was the moment when the idea” L/R Neji” renewing the history of screws in 2000 years that finally came true. It has been nearly 20 years since the first invention of L/R Neji.
 “L/R Neji” is composed of an epoch-making male screw that has a special three-dimensional screw thread that does not have a spiral structure, and two special female screws that are compatible with both the right-hand spiral structure and the left-hand spiral structure. With this structure, “L/R Neji” can be fastened without depending on the frictional force. Achieving this was a gift given by the research and development efforts of all members of NejiLaw, working night and day until completion.

From “Screw” to “Neji ”

In the process of developing “L/R Neji”, we have independently invented and developed all things related to manufacturing in order to overcome many difficulties. For instance, from manufacturing methods to manufacturing tools, devices and inspection machines to produce manufacturing tools, moreover, quality inspection methods for “L/R Neji” and inspection equipments. At last, we finally came to a conclusion that the optimum thread cross-sectional shape of “L/R Neji” was completely different from the conventional “Optimum thread angle = 60°". It was concluded that 70°was the strongest. This result was revolutionary and passed the bounds of common senses.
The in-house strength evaluation shown here is based on the question, “Under what condition makes the thread strength even stronger?" Therefore, hypotheses and tests were conducted hundreds and thousands of times repeatedly in tensile strength tests, tensile fatigue strength test, screw tightening test, torsional fatigue strength test and impact vibration screw looseness test etc. The results clearly proved that the “L/R Neji” had the same or higher strength compared to the conventional screws if the requirements were satisfied.
 Hiroshi Michiwaki, the inventor of “L/R Neji”, set a grand goal of "At first, promote the systematization of unified standards for“L/R Neji”" when NejiLaw was founded. In just 7 years from this concept, NejiLaw has completed the basis of “L/R Neji Standard”, a standard system equivalent to the “Screw Standard” that has been cultivated in its long history for more than 200 years since the Industrial Revolution. Since its founding in 2009, Michiwaki has aimed to build this unknown new standard system. From the concept of new (New), next era (Next), from Japan (Nippon), and Screws Law (Neji’s Law) system, the company is named NejiLaw, and the new standard system is named N standard. We started with the hope of spreading this new standard in the coming millennium.


Basic structure of “L/R Neji”
“L/R bolt”with its own three-dimensional structure, both right-hand thread nut and left-hand thread nut can be assembled.

“L/R Neji” “Permanent Lock Type”
Due to the ratchet structure engraved on the joint surface of the right-hand thread nut and the left-hand thread nut, we have achieved a fastening that does not loosen.

“L/R Neji” “Removable Lock Type”
Left-hand and right-hand thread nuts are integrated while being freely rotatable.
Not only do they stabilize at any position, but they can also be removed.

Product Photos

  • “L/R Neji”
    A right-hand thread nut, a left-hand thread nut
    and a “L/R Bolt” that can be screwed in both nuts.

  • Nut for “L/R Neji”
    (Top of photo) “Single Lock Type”
    (Middle and bottom of photo) “Permanent Lock Type”

  • “ L/R Clip Lock”
    Fastening tools are unneeded.
    It can be fastened/unfastened by only manual work at any position
    without loosening.

  • Basic structure of “L/R Bolt”
    In one bolt body which does not have a spiral structure,
    two kinds of nuts (right-hand and left-hand thread)
    can be screwed together.

  • Basic locking principle of “L/R Neji”
    Mechanically connect two types of nuts assembled to a bolt.
    It is locked by pushing each other or pulling each other.

About “L/R Neji”

Fastened with a combination of “L/R Bolt” with special three-dimensional screw threads and exclusive nuts with various specifications according to the purpose. There are a wide range of variations that can meet various applications and needs. Variations include: a type that cannot be removed once tightened, a type that can be removed from welding and rivetting, a type that can be removed with a predetermined torque, a type that can be fixed at any intermediate position on a bolt, a nut to prevent loosening, and a type that realizes complete prevention of reverse rotation while preventing disassembly and tampering.

This is a high-speed camera video that captures the moment of fracture
by tensile strength Test for “L/R Neji” N100 (Nominal diameter)

“L/R-ΔLoc” (L/R Delta Lock) was adopted.
This year is the 35th anniversary of sales of G-SHOCK. It is the only iron plate brand in the history of watches that has exceeded the cumulative total of 100 million units shipped.
Before G-SHOCK, it was assumed that watches break when dropped, but after overcoming many hurdles, a unique shockproof structure was invented. It was the birth of a technology that plays a central role in toughness. It was a new beginning for watch history, and this legacy of toughness continues to be handed down; G-SHOCK continues to pursue the ultimate toughness over time.
The top model G-SHOCK MRG-G2000R-1AJR was released in October 2018 and is equipped with
“L/R-ΔLoc,” the screw that never loosens. NejiLaw has stepped up to the next level as well.

Development Story
G-SHOCK, who has built a new concept of toughness for watches, came to NejiLaw in search of further advancement. Although the “L/R Neji” had already been established as a non-loosening screw, there were still many issues to resolve. Not only the material and surface treatment were limited, but also the “L/R Neji” diameter of the bolt was only 1.6 mm. Moreover, the permanent mating latch structure could not be used because it needed to be removed without breaking during repair. Thus, a new solution was invented:
“ L/R- ΔLoc”, or “Delta Lock,” a new mechanism created by Hiroshi Michiwaki applying elasto-plastic dynamics.

“L/R-ΔLoc” (Delta Lock) Fastening Mechanism
The left-hand thread “L-Nut”that is mounted first, has on one side the triangular-prism-shaped Δ (delta) part whose three apexes plastically deform the cylindrical part of the right-hand thread “R-Nut” that is mounted afterwards. “L/R-ΔLoc” mechanism is set to “deformed equal circumference” so that the outer peripheral length of the delta part and the inner peripheral length of the cylindrical part are almost equal. This cylindrical part is designed so that its deformation is within the plastic range, and when it is fitted to the delta part, it is configured so that it is pressed in the residual elastic range while accommodating a round object along the triangle. With this, it is possible to maintain a strong rocking state, and as a result, the two nuts are integrated and cannot be pulled out from the “L/R Bolt”.
What is elasto-plastic mechanics?
Most objects can be deformed by an external force, but when they do not return to the original shape after being deformed, it is known as plastic deformation (permanent deformation). Contrarily, elastic deformation is a shape change that is self-reversing after the force is removed. “Elasto-plastic mechanics” is a product that combines these different properties.

About “ZaLoc”

Completely fastened without using nuts.

“ZaLoc” consists of a “ZaLoc Bolt” with a head-seating surface locking latch and a “ZaLoc Washer” with a seating surface locking latch that meshes with it. “ZaLoc Bolt” is inserted into the tap screw holes of the object to be fastened through the “ZaLoc Washer”. Just by assembling, complete fastening without friction force was achieved.

 It consists of a bolt with a head-seat surface locking latch, and a special washer with an upper-seat surface locking latch that meshes with this. By simply tightening the bolts through the washers, it is able to tighten completely without friction force.

 It can be fastened with one general screwing tool (spanner, torque wrench, etc.) as the conventional way, and prevents loosening from mechanical fastening.
In addition, it can also be removed by applying a return torque higher than when it was fastened. Compared with the case of directly performing a locking latch process on the fastened body, the cost is remarkably low, and even when the locking latch is deformed, it can be replaced easily at low cost.

Coming Soon...