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info@crushlock.com


 

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World's Most Vibration Resistant Nut

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Vibration, the problem that affects all nut fasteners
. . . except ours

Since the nut fastener became widely used during the industrial revolution, countless lives have been lost simply because the nut vibrated loose. All nut fasteners today use friction for vibration resistance, since vibration cancels friction, all nut fasteners must eventually loosen. Vibration is the bolted joints worst enemy, a loose nut can lead to bolt stretching and catastrophic failure.
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Currently all nut fasteners on the market, including conventional, special design single and two-piece locking nuts, have the same inherent weakness - the nut will vibrate loose. There have been many attempts to overcome the nut fastener's inherent problem including the invention of various special locking one and two-piece nut designs and adhesives, all of which will only slow down the loosening process, not preventing it.

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Introducing The Crushlock Permanent Nut

 

How the Crushlock Permanent Nut works.

 

 

 

Why the Crushlock Permanent Nut works.

 

A new classification of nut fastener is born

Crushlock Permanent Nut is a one-piece, all-metal nut fastener that is manufactured in all grades of steel and stainless steel. Crushlock Permanent Nut's patented design presses a threaded "Flying Saucer" shaped locking component into the Crushlock Permanent Nut body. This has resulted in what many fastener professionals thought impossible, a nut fastener with, not only extreme vibration resistance, but also greatly exceeds the industry standards in Strength and Performance. Crushlock Permanent Nut is based on and has all the advantages of a standard nut without the inherent vibration loosening problem. Crushlock Permanent Nut is manufactured in industry standard sizes, thread pitch, materials and grades. Crushlock Permanent Nut is free-spinning and resembles a conventional nut, it installs easily with standard tools on standard bolts and studs.

 

 

Crushlock Permanent Nut is the only nut fastener in the world that does not use "contact friction" for vibration resistance, instead it uses permanent internal pressure. The internal and external pressure of the Crushlock Permanent Nut are equal when installed. Because vibration cannot affect Crushlock Permanent Nuts internal pressure, vibration is no longer a factor and has no effect on a properly installed Crushlock Permanent Nut. Laboratory testing has shown that Crushlock Permanent Nut exceeds all vibration standards (Aerospace, Automotive, Construction, Railroad, etc.). Once installed, Crushlock Permanent Nut must be destroyed to be removed, it is physically impossible for Crushlock Permanent Nut to vibrate loose.

 

 

The strength of Crushlock Permanent Nut is unsurpassed, depending on the Crushlock Permanent Nut size and material, Crushlock Permanent Nut has been tested to hold over 500% of the standard nut torque. Crushlock Permanent Nut is able to accomplish this feat by using our innovative patented "Flying Saucer" technology. The key to designing a nut that holds over 500% torque of a conventional nut, is the understanding that the vast majority of nut stress is on its first two threads. It is these first two threads on the "Flying Saucer" that are pressed into the body of the Crushlock Permanent Nut during installation, creating permanent internal pressure. The spiraling seating action of the "Flying Saucer" being pressed into the Crushlock Permanent Nut body prevents the first two threads from stripping, and allows greater applied torque and pressure. The increased torque and pressure from Crushlock Permanent Nut greatly increases bolted joint strength. Greater pressure equates to a stronger bolted joint.

 

 

Crushlock Permanent Nut was engineered for extreme performance from its inception by using computer modeling in 2D, 3D and Finite Element Analysis(FEA). Crushlock Permanent Nut performance is permanent, once installed on a bolted joint, Crushlock Permanent Nut keeps the bolted pressure even if the nut is destroyed and profile cut-in-quarters. Crushlock Permanent Nut cannot release pressure even if cut-in-half with the bolt head cut-off, photos below. Laboratory tests show that when Crushlock Permanent Nut was over torqued during installation to past the point of nut failure, it would still retain its pressure and remain bolted. In other words, Crushlock Permanent Nut continues to function and hold pressure even after nut integrity failure. All other nut fasteners on the market today would violently release its pressure and fall-off once nut integrity fails.

 

Crushlock Permanent Nut uses the characteristics of Extreme Vibration Resistance, Unsurpassed Strength and Extreme Performance as a Bolted Solution. Separately each characteristic has a distinct advantage, the combined characteristics creates a nut fastener that is "The New Standard For Mission Critical Applications". When permanent nut performance is required for extreme conditions and environments in extreme applications, Crushlock Permanent Nut is the only solution.

Crushlock Permanent Nut Advantages

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The advantages of highly advanced nut fastener technology


  • Innovative patented locking system.
  • Material strength vibration resistance.
  • Extreme performance, retains pressure even when bolted joint is profile cut-in-quarters.
  • Retains pressure even when nut is over-torqued.
  • Lightweight. Weighs the same as a standard nut.
  • Strength to weight ratio is better than Titanium.
  • Uses industry standard threads, bolts and studs.
  • Uses standard hand and power tools to install.
  • Unsurpassed strength and performance.
  • Made to all standards in steel and stainless steel.

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  • Removeable but not reuseable, nut and bolt is destroyed if forced off.
  • Holds over 500% torque with increased pressure.
  • Patented technology prevents nut dilation.
  • Superior clamp pressure creates the world's strongest bolted joints.
  • Stronger and faster to install than one and two-piece lock nuts.
  • Impervious to heat, excellent for high heat applications.
  • Can be manufactured to your specifications.

Crushlock Permanent Nut Technology

  • How Crushlock Permanent Nut Works

    Learn how the Crushlock Permanent Nut works.

    Read More
    Crushlock Nuts patent pending permanent locking technology

  • Crushlock Permanent Nut Design Theory

    Learn the theory behind Crushlock Permanent Nut innovative design.

    Read More
    Slide 2a

  • Crushlock Permanent Nut Finite Element Analysis(FEA)

    Crushlock Permanent Nut's FEA computer simulation testing.

    Read More
    Crushlock Nuts patent pending permanent locking technology

  • Learn Why Crushlock Nut

    has Extreme Vibration Resistance

    Understanding what makes the Crushlock Permanent Nut the only nut fastener in-the-world with Extreme Vibration Resistance.

    Read More
    Slide 4

  • Junker Machine Vibration Testing

    Learn why Crushlock Permanent Nut exceeds DIN25201 vibration standards testing parameters for all industries including Aerospace, Automotive, Railroads, Mining, etc.

    Read More
    Slide 2a

  • Learn Why Crushlock Permanent Nut is The World's Strongest Nut

    Learn why the Crushlock Permanent Nut can handle more pressure and torque than a standard nut fastener.

    Read More
    Slide 3

  • Crushlock Permanent Nut Torque Strength Comparison

    Learn how much more torque Crushlock Permanent Nut can hold, compared to a conventional nut.

    Read More
    Slide 4

  • Crushlock Permanent Nut Extreme Performance

    Learn how Crushlock Permanent Nut achieves extreme performance.

    Read More
    Slide 4

  • Stress, Forces and Nut Dilation

    Learn how Crushlock Permanent Nut solved the nut dilation problem.

    Read More
    Slide 3




Crushlock Nut Applications

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Crushlock Permanent Nut is in a class by itself - The Permanent Nut class

Applications that could benefit by using the Crushlock Permanent Nut.


  • Aerospace
  • Automotive
  • Civil Engineering
  • Construction
  • Dam Projects
  • Elevator
  • Farming Equipment
  • Guard Rails
  • Heavy Duty Applications
  • High Performance Applications
  • High Vibration Applications
  • Industrial Equipment
  • Infrastructure
  • Manufacturing
  • Marine Applications
  • Medical Industry
  • Military
  • Mining
  • Motorcycles
  • Motorsports Racing
  • Nuclear Power
  • Railroad
  • Recycling
  • Rock Crushers
  • Safety Applications
  • Shipping Industry
  • Steel Industry
  • Steel on Steel Applications
  • Street Lights
  • Street Signs
  • Transportation
  • Oil Industry

Crushlock Permanent Nut Development

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Creating the Crushlock Permanent Nut . . . what a journey

The Crushlock Permanent Nut was initially named the Arnold Permanent Nut, in honor of the inventor. The journey began in March 2011 when Crushlock Permanent Nut inventor, Mr. Arnold, was watching a short Japanese news brief about a fastener company in Japan. This company made what is advertised as the world's most vibration resistant two-piece locking nut. During an interview, the owner/inventor stated he has been trying to invent a one-piece nut that is not affected by vibration for thirty years, but was unable to do so. This one-piece nut had interest from the aerospace companies because it would save weight and not loosen.

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That night, Mr. Arnold thought about how a one-piece permanent nut could be designed. The only permanent nut that he could think of was two nuts torqued down and welded together. This works because the double nuts have "permanent internal pressure". Mr. Arnold decided that whatever the new nut design looked like, it would have to incorporate the same "permanent internal pressure" as the welded double nuts. Twenty minutes later he drew the first drawings of the Crushlock Permanent Nut. This new permanent nut incorporates and surpasses all of the advantages of one and two-piece locking nuts with none of the disadvantages. Until that point, the concept of a "permanent nut" was unheard of with many fastener professionals believing it was impossible.

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Sizes & Availability

 

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Crushlock Permanent Nut the Ultimate in High-Performance Nut Fasteners

We stock the following size permanent nuts:

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SAE size 3/8X16 Stainless steel (grade SUS304)
(Crushlock Permanent Nut 92 ft./lbs. vs Std. nut 17.5 ft./lbs) Holds over 500% of std. tq.
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SAE size 1/2X13 Flanged (grade-8)
(Crushlock Permanent Nut 202 ft./lbs. vs Std. nut 96 ft./lbs) Holds over 200% of std. tq.

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FAQs

 

A: Exactly. The Crushlock Permanent Nut is a revolutionary invention that many people, including fastener professionals believe impossible. "Highly advanced technology" is applied to an ancient machine, with results that are exceptional, in every aspect of nut fastener performance.

 

 

A: Crushlock Permanent Nut is the only nut fastener that does not use contact friction for vibration resistance. Instead of friction, Crushlock Permanent Nut uses permanent internal pressure. Since the internal pressure is permanent, vibration is no longer a factor. It is physically impossible for a properly installed Crushlock Permanent Nut to vibrate loose.

 

 

A: You haven't heard of a permanent nut before because Crushlock Permanent Nut was recently invented and uses innovative new patented technology.

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Crushlock Permanent Nut Comparison Chart

 

Crushlock Patents

 

Sold Exclusively by:


http://www.Crushlock.com

 



















Understanding How Crushlock Permanent Nut Works



1) Unattached patented Crushlock Permanent Nut "Flying Saucer" locking component. 2) Unattached patented Crushlock Permanent Nut body. 3) Fully assembled Crushlock Permanent Nut in the uninstalled position. 4) Partly installed Crushlock Permanent Nut. Note: The smaller inner space has permanent internal pressure. 5) Crushlock Permanent Nut in the fully installed position. Note: There is still a little space between the installed "Flying Saucer" and the Crushlock Permanent Nut nut body. This space is intentional, it allows Crushlock Permanent Nut to achieve much higher applied torque while reducing the amount of stress on the threads.
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Crushlock Permanent Nut is free-spinning and installs as quickly and easily as a conventional nut.
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Once the torque created pressure overcomes the resistance of the Crushlock Permanent Nut "Flying Saucer" locking component it starts to deform/deflect and press into the Crushlock Permanent Nut body. The collapsing Crushlock Permanent Nut "Flying Saucer" component functions with equal pressure on both the contact face and the inside of the Crushlock Permanent Nut. Once torqued down, the internal pressure is permanent and cannot be released even if the head is cut-off of the bolt or if the bolted joint is profile cut in quarters.
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All nut fasteners on the market, except Crushlock Permanent Nut, rely on contact friction for vibration resistance. Due to this fact, all nut fasteners loosen because the vibration cancels friction, therefore all nut fasteners must eventually loosen. Crushlock Permanent Nut resolves this problem by using permanent internal pressure. It is physically impossible for vibration to loosen a correctly installed Crushlock Permanent Nut, this makes Crushlock Permanent Nut the only solution for mission critical applications.

Crushlock Permanent Nut Design Theory.



In a standard nut bolted joint (Fig.1) the (clamp load) is only about 75% of the pressure (proof), about 25% pressure is lost to friction. Since all locking nut fasteners including special one and two-piece locking nuts use friction for vibration resistance, more bolted joint pressure is lost. The greater friction (greater vibration resistance) a locking nut has, the less pressure and the less strength the bolted joint has. All locking nut designs trade vibration resistance for bolted joint strength, the greater the vibration resistance, the weaker the bolted joint. This is why you never see any locking nut design with an increase in bolted joint pressure/strength.

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With double nuts, a jam nut with a standard nut (Fig.2) an attempt for increased vibration resistance is made while retaining bolted joint strength/pressure. Of course, this type of bolted joint will still vibrate loose, it will just take a little longer because now two nuts must loosen.

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Crushlock Permanent Nut patented "Flying Saucer" locking technology (Fig.3 shown in green) is the only solution for increased pressure and increased (permanent) vibration resistance. Crushlock Permanent Nut is free spinning like a standard nut, uses standard threads and installs with standard tools.

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During installation Crushlock Permanent Nut's "Flying Saucer" locking component (Fig.4 shown in green) starts to deform/deflect and creates equal pressure on the contact face and internally in the Crushlock Permanent Nut body (Fig.3 shown in blue).

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Once fully installed (Fig. 5) Crushlock Permanent Nut permanent locking pressure is encapsulated within the Crushlock Permanent Nut body, permanent internal pressure which is reinforced by the tensile and compressive strength of the nut's material.

Understanding how Crushlock Permanent Nut has Extreme Vibration Resistance



 

Left drawing: When Crushlock Permanent Nut is installed, the "Flying Saucer" is pressed into the Crushlock Permanent Nut body (red circle). Although both the treads of the "Flying Saucer" and the nut body remain in time (in phase) with the bolt, there is a difference of thread timing between the "Flying Saucer" and the nut body. At this point permanent internal pressure is created that is equal to the external pressure of the fastener contact face.

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Center photo: This is a photo of an 1X8 size Crushlock Permanent Nut that has been installed and forcibly removed. Note: The threads of the Crushlock Permanent Nut has been broken-off and stripped. Crushlock Permanent Nut's vibration resistance is its material strength. Crushlock Permanent Nut must be destroyed to be removed. Note: The Crushlock Permanent Nut threads only strip when forced-off, Crushlock Permanent Nut threads do not strip and are not damaged during installation.

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Right photo: Shows a destroyed bolt that is a result of forcibly removing an installed Crushlock Permanent Nut. Note: The threads are stripped for the entire length of the bolt. This Crushlock Permanent Nut and bolt was installed oiled during lab testing.

Understanding What Makes Crushlock Permanent Nut The Strongest Nut in the world



The key to understanding why Crushlock Permanent Nut is able to hold more torque and pressure compared to a standard nut is, the realization that the vast majority of nut stress is on its first two threads (red circles) from the nuts contact face.

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It is these first two threads that are pressed into the Crushlock Permanent Nut body during installation. Along with creating permanent internal pressure, the spiraling seating action of the "Flying Saucer" being pressed into the Crushlock Permanent Nut body prevents the first two threads from stripping and allows Crushlock Permanent Nut greater applied torque and pressure.

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Newtons third law. When the "Flying Saucer" pushes against the bolted joint, the bolted joint pushes back and presses the "Flying Saucer" into the Crushlock Permanent Nut body. The "Flying Saucer" threads do not strip because there is a space for the nut material to flow into (center drawing). The "Flying Saucer" is pressed into the Crushlock Permanent Nut body at the same rotational rate and distance as the tread timing.

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The first two threads on a standard nut will strip when over tightened, because there is nowhere for the thread material to flow into (right drawing).

Crushlock Permanent Nut Designed for Extreme Performance



Along with having Extreme Vibration Resistance and the strongest nut fastener in the world, Crushlock Permanent Nut also has the characteristic of extreme performance. Performance so extreme that Crushlock Permanent Nut will stay-on the bolt and retain its pressure (function) even when it is cut in quarters. In other words, Crushlock Permanent Nut still works even after nut integrity fails. All other nut fasteners on the market today will violently release pressure when nut integrity fails and fall-off.

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Crushlock Permanent Nut's extreme performance is achived by its revolutionary patented technology. Once Crushlock Permanent Nut is installed, it cannot release its permanent internal pressure. It is this permanent internal pressure that allows the Crushlock Permanent Nut to perform even after being destroyed. Nut fastener performance does not get better than this.

Crushlock Permanent Nut Finite Element Analysis Testing



Finite Element Analysis (FEA) is a type of computer program that uses the finite element method to analyze a material or object and find how applied stresses will affect the material or design. FEA can help determine any points of weakness in a design before it is manufactured. FEA is mostly used in aerospace and other high-stress applications. The analysis is done by creating a mesh of points in the 3D shape of the object that contains information about the material and the object at each point for analysis. FEA can analyze the effect of stress, vibrations, fatigue, and heat transfer.

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FEA aided our design engineers to determine the final Crushlock Permanent Nut design. Crushlock Permanent Nut FEA models have been tested with several materials and standards including SAEJ995 and DIN934/ISO4032 and the results were outstanding. The different colors on the FEA images represent the different amounts of stress. FEA computer testing has shown that Crushlock Permanent Nut is a "clean design" with no weak or problem points and will not stress crack when in use.

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Crushlock Permanent Nut technology is so innovative that a conventional 1X8 size nut at maximum torque has more stress than our 1X8 size Crushlock Permanent Nut at over 300% normal torque.

Crushlock Permanent Nut is the only Extreme Vibration Resistance Nut in the world



A Junker test is a mechanical test to determine the point at which a bolted joint loses its preload when subjected to shear loading caused by transverse vibration. Design engineers apply the Junker Test to determine the point at which fastener securing elements – such as lock nuts, wedges and lock washers – fail when subjected to vibration. The Junker test and has been adopted into international fastener standards such as DIN 25201-4,5 the Junker test is the established method used for analyzing the self-loosening behavior of secured and unsecured threaded fasteners under transverse loading conditions by vibration testing.

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The above graph shows the DIN25201 Junkers standard testing results for a conventional nut, shown in black. The DIN25201 Junkers standard testing pressure is about 25,000lbs.

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The above graph also shows the Crushlock Permanent Nut operational pressure is over 300% higher than the Junkers testing standard. Crushlock Permanent Nut's vibration resistance is so strong, that the Junkers test machine broke several times during testing at Crushlock Permanent Nut's normal operational pressure to no avail. Crushlock Permanent Nut's performance capabilities greatly exceeds the Junkers testing standard parameters. In other words, the Junkers testing machine was not able to loosen the Crushlock Permanent Nut when tested at Crushlock Permanent Nut's normal operational pressure. More over, the Crushlock Permanent Nut broke at least five Junkers Vibration Machine load cells during testing, before the testing lab declared that our nut exceeded the capabilities of their testing equipment.

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Since Crushlock Permanent Nut must be destroyed if forced-off or removed, it is physically impossible for vibration to loosen it when installed at normal operational (maximum) pressure.

Crushlock Permanent Nut can hold over 500% more torque vs. a standard nut

Nut fastener torque is defined as a rotational moment; it is a measure of how much twisting is applied to a fastener. The units used to measure torque are in the form of force times length. Usually measured in Newton/metres (Nm) if metric or ISO units are used or foot/pounds (ft./lbs.) when American or SAE units are used.
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Note: Standard nut fasteners maximum torque is 100%. All torque percentages are torque values when installed with oil. Each application is unique, it is the responsibility of the end user to test and determine is Crushlock Permanent Nut is suitable for your application. Your results may vary. Material grades SAE grade-8 and ASTM 10.9 are interchangeable.
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1) SAE size 3/8X16 Stainless steel (grade SUS304) (Crushlock Permanent Nut 92 ft./lbs. vs Std. nut 17.5 ft./lbs.) Holds 525% of std. tq.
2) SAE size 1/2X13 Flanged (grade-8) (Crushlock Permanent Nut 202 ft./lbs. vs Std. nut 96 ft./lbs.) Holds 210% of std. tq.
3) SAE size 9/16X12 (grade-8) (Crushlock Permanent Nut 222 ft./lbs. vs Std. nut 77 ft./lbs.) Holds 288% of std. tq.
4) SAE size 3/4X10 (grade-8) (Crushlock Permanent Nut 405 ft./lbs. vs Std. nut 282 ft./lbs.) Holds 143% of std. tq.
5) SAE size 1X8 (grade-8) (Crushlock Permanent Nut 1800 ft./lbs. vs Std. nut 454 ft./lbs.) Holds 396% of std. tq.
6) METRIC size M10 x 1.5 (grade-8/10.9) (Crushlock Permanent Nut 89 ft./lbs. vs Std. nut 40 ft./lbs.) Holds 222% of std. tq.

Crushlock Permanent Nut Stress, Forces and Nut Dilation



Stress, Forces and Nut Dilation. Under load, the wedging action of the threads causes dilation of the nut body resulting in an increase in the minor diameter of the nut and nut body swelling on the contact face. This reduces the effective shear areas of both the external and internal threads weakening the holding strength of the nut fastener. The threads are the weakest part of a conventional nut fastener.

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Fig. 1 Conventional and all other nut designs except Crushlock Permanent Nut "Have Nut Dilation".
1) Straight red line shown for reference purposes. Note the bottom of the nut body "is not uniform"and swells. 2) Red arrow indicates the direction of stress. The load stress creates nut dilation and nut swelling on the contact face. 3) Red arrow indicates the direction of deflection of the nut body, nut swelling on the contact face. 4) Red circle. Black colored area indicates the space created because of nut dilation. The larger black area located in between the nut body and bolt on the contact face shows the reduced contact area of the major and minor threads. The reduced contact area of the threads results in the weakening of the nuts holding strength. 5) Small red circle shows the nut swelling of the nut fastener body on the contact face.

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Fig. 2 Crushlock Permanent Nut fastener innovative design "Prevents Nut Dilation".
1) Red lines shown for reference purposes. Note the bottom of the Crushlock Permanent Nut, the contact face "is straight and uniform with out Nut Dilation". 2) Red arrow pointing downwards indicates the direction of stress when Crushlock Permanent Nut is installed. 3) Red arrow pointing upwards shows the direction of force when Crushlock Permanent Nut is installed pressing the "Flying Saucer" locking component is pressed into the Crushlock Permanent Nut body. 4) Red circle shows the internal permanent pressure space, this space is intentional. The threads on the "Flying Saucer" locking component does not touch the threads on the Crushlock Permanent Nut body at any time. This insures that all Crushlock Permanent Nut threads are intact with minimal thread stress, and maximum thread strength. Note that on all nut fasteners designs except Crushlock Permanent Nut, the majority of the thread stress is on the first three threads. 5) Red arrow pointing in direction of Crushlock Permanent Nut load stress. Another advantage of having the internal space is that all of the load stress is transferred from the threads which are the weakest part of the nut, to the outside of the Crushlock Permanent Nut body which is the strongest part. This technology enables Crushlock Permanent Nut to handle increased torque and pressure because the load is redirected away from the fasteners threads which is the weakest part of the nut fastener, to the strongest part of the Crushlock Permanent Nut body which has a larger surface area for greater load distribution.