Kawasaki KLR Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
1,481 Posts
Discussion Starter #1
https://www.google.ca/search?q=split+type+lock+washer&espv=2&tbm=isch&imgil=8PHmK-No_6ILEM%3A%3Bhttps%3A%2F%2Fencrypted-tbn2.gstatic.com%2Fimages%3Fq%3Dtbn%3AANd9GcQ06gJaRLRE7OG8LOAL22gdVrRaPJK1u9_LjMa_T6tJUntmMDV3%3B558%3B361%3Bc0hfMp-y8S9D5M%3Bhttp%253A%252F%252Fwww.boltdepot.com%252Fchrome-nuts-and-bolts.aspx&source=iu&usg=__mbB5X5cjo5rxPiMQgAHOi542-Bw=&sa=X&ei=2uW5U7TEO4KgogS66YDABw&ved=0CDoQ9QEwAg&biw=1366&bih=643#facrc=_&imgdii=_&imgrc=8PHmK-No_6ILEM%3A;ccx1jgA_57nixM;http%3A%2F%2Fwww.boltdepot.com%2Fimages%2FChrome%2Fchrome-split-lock-washers.jpg;http%3A%2F%2Fwww.mechanicaldesignforum.com%2Fshowthread.php%3F43-Question-on-types-of-washers;558;361

Don't use lock washers of the split type! These are the ring shaped washers which are split and bent into a spiral.

Before some one sets fire to my shorts, please consider that automotive manufacturers stopped using them for normal production over 20 years ago because they found them to be unreliable. These washers function by placing a tension load onto the fastener which intends to keep the fastener from loosening by keeping the threads loaded. They also are intended to dig into the head of the fastener and the work surface.

Problems, most grade 5 (SAE bolts) and 8.8 (metric) are under a tensile load which far exceeds the tensile loading provided by the split washer. This means that the washer makes no contribution to loading the fastener.
In addition, Grade 5 and 8.8 bolts are too hard for the split type washer to penetrate sufficiently to get a good grip. This also makes these washers unnecessary.

Another problem is that the tensile loading of the fasteners (Grade 5 and above and 8.8 and above) is often sufficient to break the washer which then can work out of place removing all load from the fastener. This is not good!
The finisher is that these washers dig a piece out of the soft aluminum every time they are used.

Use a good quality flat washer. Put the flat washer onto the bolt or cap screw in the correct direction (put the rounded edge side of the washer toward the head) so that the washer does not dig into the fillet under the bolt head and possibly initiate a head failure.

Tighten the fastener correctly and use a locking device such as safety wire, cotter pin, lock nut or Loctite if desired.

Forget lock washers unless there is some unusual requirement.

While on the subject.....make sure that you are using a hardened flat washer rather than a mild steel one as is the case with typical hardware store washers which are intended for use with Grade 2 or below SAE fasteners (or metric equivalent). If you use a soft washer and then tension (tighten) the fastener to specs all will seem well but over time the soft washer will give under the pressure and will press thinner. This will remove the tension from the fastener and so the clamping force will be lost. With the loss of tension and clamping force goes head gaskets, breakage of bolts under reciprocating loads and so on. Bad idea!

Another one commonly not understood is the issue of locking nuts. A locking nut which has a deformed end (one end is pressed out of round) may be rated for use with high strength fasteners (SAE Grade 8 or metric12.8 and above).

A nylock nut with a rod of nylon (or other plastic sorts stuff) which protrudes through a radial hole drilled into the threaded area of the nut) may be also suitable for high strength fasteners. A nylock nut with a ring (washer) of nylon secured in one end of the nut is only suitable for low strength bolts (cap screws) because a hardened nut (for high strength) cannot be crimped over the washer. Easy to tell!
 

·
Administrator
Joined
·
3,568 Posts
Anybody want to buy some lock washers!!???
 

·
Administrator
Joined
·
3,568 Posts
When the plant I worked in shut down I bought a bolt bin full of imperial and metric fasteners, all stainless steel for $20. Have a supply of bolts I'll never use in my lifetime, including split lock washers.
 

·
Registered
Joined
·
1,481 Posts
Discussion Starter #5
How about posting a photo to really upset people? ;-)

Any decent collection of fasteners for $20.00 is a steal of a deal. Likely they're North American manufactured too? ....grumble..... ;-)

Stainless are another bed of worms. So far as I can recall, there is only one grade of stainless which even equals Grade 5/Metric 8.8 so people who think that they are installing better fasteners by switching to stainless are generally in error. Add to that that stainless aren't particularly compatible with aluminum and become harder than glass when heated and I avoid stainless. Stainless Allens are soft as butter which means the hex drive strips out easily.
 

·
Registered
Joined
·
378 Posts
:desismiley1:Thanks Normk for the great info...

:12: time for a reality check on the KLR...It is over 20 years old and still uses cotter pins to keep the wheel on, it has not advanced to lock washers, so maybe they will leap over that in the next gen in about another 10 years....

Ride Safe
 

·
Premium Member
Joined
·
5,516 Posts
I don't see how you can go wrong with a cotter pin. That's about as failsafe as you can get. When I used to work on helicopters, we had a lot of nylon lock nuts on the flight controls but they were still castellated and required cotter pins.

Surprisingly, some of the bolts you would think were the most critical, like those that secured the transmission to the top of the fuselage, didn't have any kind of locking component at all: you just torqued them down, rechecked the torque after about 10 flight hours then forgot about them for the next 500 hours.

A lot of bolts that were lockwired required you to cut the wire off after 10 hours and re-check the torque on them to make sure they were still tight, then rewire them. Lockwire isn't designed to make sure a fastener maintains the proper torque, it's just to make sure it doesn't work loose and fall completely out.

Other bolts that had self-locking castellated nuts and a cotter pin also had spring-loaded, self-retaining tangs kind of like a door latch so if somehow the cotter pin and nut came off, the bolt would still at least stay in place. Some had a small pin in the bolt head you had to push with a pick or small allen key to get them to release: others you just pushed in with your fingers to get them out of the hole.

I've shed more blood dealing with lockwire and cotter pins than most have donating at the Red Cross.

I use safety wire on my oil drain plug but other than that rely on Loctite to keep things in place.

I also use "anti-sabotage lacquer" or "Torque Seal" on things like my front fork axle nut/pinch bolts, swingarm nut, link nuts around the shock, front hub speedo cable, subframe bolts, etc. so I can just take a quick look and make sure nothing's working loose.

http://www.aircraftspruce.com/pages/ap/seal/f900.php
 

·
Registered
Joined
·
378 Posts
No offence but the last time I listened to an helicopter tech was at a campsite, it involved drinking, a lot of high wind, tape for fixing bullet holes on military copters, and the following morning not being able to pull back the flaps on the tent anymore...

yes they can fix things....permanently...:50:
 

·
Premium Member
Joined
·
5,516 Posts
I like the yellow torque seal because it's the easiest to see. The only problem with it is that somebody is always asking you what it is.

AircraftSpruce has some handy 1 lb. safety wire rolls, too. It can be used for a lot of things besides safetying bolts. It's a handy diameter, plus it's tough and pliable. You can pull on it hard and bend and twist it a lot before it breaks. I take some out of the dispenser and roll it around a little dowel rod and put it in my tool kit. It's just handy to have around the shop in general.
 
1 - 10 of 10 Posts
Top