Sign up Calendar Latest Topics Donate
 
 
 


Reply
  Author   Comment  
Walt Strong

Sr. Member
Registered:
Posts: 889
Reply with quote  #1 
I found this interesting product:
http://www.katofastening.com/lockone.html

I have not used it, nor do I sell it.

Walt
Danny Harvey

Sr. Member / Moderator / Supporter
Registered:
Posts: 1,403
Reply with quote  #2 
That may be worth the small investment.

As a practice, we replace all hardware when we do an alignment but apparently that practice is not used by many others because we always find reused and ineffective lockwashers.
Walt Strong

Sr. Member
Registered:
Posts: 889
Reply with quote  #3 
The Kato Lockone restrains the top of the nut, and it is not like a lock washer between nut or bolt head and the base metal. A good lock washer is the Nord Lock Washer:
http://www.nord-lock.com/nord-lock/wedge-locking/washers/introduction/?campaign=328043079&content={creative}&keyword=bolts%20washers&placement={Placement}&utm_source=bing&utm_medium=cpc&utm_campaign=Bing_Nord-Lock&utm_term=bolts%20washers&utm_content=Nord-Lock%20Washers

Walt
John from PA

Sr. Member
Registered:
Posts: 963
Reply with quote  #4 
Quote:
Originally Posted by Danny Harvey
That may be worth the small investment.

As a practice, we replace all hardware when we do an alignment but apparently that practice is not used by many others because we always find reused and ineffective lockwashers.


Reusing can be expensive...see https://www.fastenal.com/en/77/reuse-of-fasteners
Curran919

Avatar / Picture

Sr. Member / Supporter
Registered:
Posts: 599
Reply with quote  #5 
I always liked the Nordlock washers because the concept is so simple to understand. I've never used them, but the testing they performed in their marketing vids seemed rather trustworthy. On the other hand, I have a hard time trusting these KATO lock nuts. Part of that is probably that the method of operation is not clear. They advertise axial and radial forces, but this really doesn't mean much. They really need to better describe this. Furthermore, I am really worried when they say "if the lockone isn't touching the nut, just handtighten until it touches." What?

I suspect that maybe as the axial pressure from the nut increase (as the nut starts to loosen off), then the inner wires of the lockone will constrict around the bolt and prevent itself from rotating?
electricpete

Sr. Member
Registered:
Posts: 651
Reply with quote  #6 
The use of Kato Lockone would be limited to through bolts fastened at the other end by a nut AND having three extra threads.  That eliminates a lot of applications. 

We tend to use a fair amount of Loctite anaerobic threadlockers where we have concerns about fastener loosening. The theory is that the substance doesn't cure unless it in the presence of metal and absence of oxygen.  So it won't cure in the tube. It won't cure after you open the tube. It won't even cure after you apply it to the metal part. It begins curing only after you assemble the part in a manner that excludes air (make up the threads). There are a variety of grades depending on the application.  Lighter locking gradese can be removed easily with a wrench. Heavier locking needs heat assistance during removal. 

Besides threadlocking, Loctite makes similar anaerobically curing compounds for use on cylindrical fits.  Could potentially have some use in troubling applications of movement of coupling hub on shaft or fan/impeller on shaft or POSSIBLY a cheating way to repair loose anti-friction bearing fits. 



Dan Timberlake

Sr. Member
Registered:
Posts: 116
Reply with quote  #7 
One thing that makes sense to me in the Nordlock literature is that when used with a nut and bolt combo,  one  Nordlock pair is required under the bolt head AND another pair is required under the the nut.

That Junkers test condition generally cited represents Forced sliding of the two bolted components over +/- 0.3 mm/12 MILS or more.  To allow this to happen without the proper concern (ANY concern?) for the actual force required to cause this motion in a real bolted assembly, the two bolted components are separated by roller bearings.
https://media.boellhoff.com/files/jpg1/nord-lock-junkers-vibrationstest-aufbau.jpg

To me this is an unthinkable operational aberration, indicating a complete failure by the bolted joint designer, or the installation procedure.

Slapping NordLock washers in a bolt/nut assembly that is undertightened, or with soft washers that allow embeddment and fastener relaxation at nominal torque, or holding components with rough faying/mating surfaces that will embed over time even without relative motion, or with bolts with insufficient grip length, is not going to keep the components together and aligned. The nuts and bolts may not rotate relative to each other during this horrorshow, but the shims are going to be chewed up pretty soon at 900/1200/1800 slides per minute.  Is there a real benefit to that ?  Better to design and install the bolts and nuts so that motion and loosening don't happen
RustyCas

Avatar / Picture

Admin
Registered:
Posts: 1,810
Reply with quote  #8 
Quote:
Better to design and install the bolts and nuts so that motion and loosening don't happen.


Exactly, Dan.  It doesn't matter if the nut is "loose".... once the nut moves - ANY - you have lost the original tension in the bolt, and likely the friction in the joint.  I also much prefer through-bolts as opposed to studs.  On a machine that gets replaced fairly often, a stud is likely to stretch, eventually becoming "plastic" and the joint won't stay tight.  As Dan says, better to use the proper fasteners and make sure all the surfaces are smooth, flat, and devoid of lubricants.  If the joint is designed -- and executed -- properly, a fastener is not going to come loose, no matter the vibration.  

__________________
"The trend is your friend"
electricpete

Sr. Member
Registered:
Posts: 651
Reply with quote  #9 

That’s an interesting perspective on the Junker test. I agree that watching it, looks very unrealistic both in Dan’s video and in the Kato video.  I guess it is supposed to represent an “accelerated life” test under an assumption that the parts will lose tension and undergo sliding motion at some point (which is a very questionable assumption).    And it seems like a standard test, with an ASTM number. Frequently referenced on bolt websites:

http://www.boltscience.com/pages/vibloose.htm

and

https://engineerdog.com/2015/01/11/10-tricks-engineers-need-to-know-about-fasteners/

I agree with the fundamental’s Dan listed. The bright side for this Kato device is that it is not installed between nut and joint, rather it is installed on the threads outside the nut, so it shouldn’t interfere with those fundamentals (unlike a helical split lockwasher which goes between nut and joint creating potentially lower contact area with more embedment problems, and also longer joint which has lower joint stiffness which can increase the fraction of joint cyclic loading seen by the bolt).   So the Kato device may or may not help, but I doubt it would hurt. I'm not rushing out to buy any though. 

Previous Topic | Next Topic
Print
Reply

Quick Navigation:

Easily create a Forum Website with Website Toolbox.