Spring washers or nylock nuts

[Andrew]

Hi I have a question, this question has been promted by me ordering some front suspension parts for my Herald. The parts were delivered with all the relivant nuts and washers. On opening the packaging I discovered that there were a pack of plain nuts and Spring washers and a duplicat set of nylock nuts and plain washers so my question is which is best to fit and why.

What is the advantage of either the spring washer set up or the nylock option not just on suspension but on any part requiring to be fastened

I know where heat is involved you should not use my lock nuts for obvious reasons, but on any other installation which is best

 

Regards

Andrew

[Rabbit]

I would use nylocks and plain washers on suspension parts etc. Nuts and spring washers cannot be tightened (I think) to a specified torque. Interesting one this as no doubt those more expert than myself will quote otherwise but then I have never had anything fall off or come unscrewed etc using nylocks. Obviously you are right in not using where heat is involved. Even if not torqueing up, nylocks and plain washers can be done up more firmly. 

[Pete Lewis]

we did lots of tests when torque control became the thing to develop in the late 60s 

 

spring washers were found to be pretty useless,  narrow surface area , defoemation and lost torque and they do little for anything which can undo itself , it holds the nut for a short period and then the nut drops off.

 

nyloc or stiff nut are the way but we also found plain nuts on good washers gave the best reliable results and in the 1993 to 2003 

chassis fittings all reverted to plain nuts  and there you go   some stiff nuts can  absorbe a lot of the the torque applied 

its all down  to preference

just my experience 

Pete

[Andrew]

Hi guys

Interesting I have premed your replys and rebuild my front suspension yesterday with plain washers and the nylons option. The reason for this is I have a Haynes manual and I was referring to this during the rebuild for the torque wrench settings and they refer to all part with plain washers and nylock nuts.

 

It does Beg the question are there any installations wher Spring washers are best ( heat sensitive parts excepted)

Andrew

[Pete Lewis]

theres lots of locking or ideas to retain loosening nuts depends on the application there flat spring square spring

internal star and external star all designed to be somewhat shake proof

 

if yo use a nyloc in a plain nut situation its worth doing a simple test to  determine how much of the initial torque it absorbed buy the 

its stiffness ,  can be up to 10lbft   depends on the diameter and add that to the specified range

 

but a decent spanner with a good hand applied load  applied will give you very close to the spec anytime   thats why big spanners are longer than small ones , one can say many torque figures were introduced to allow unskilled workers achieve with calibrated tooling a consistent assembly result 

 

bit like putting front on some triumph springs when it did not matter , but it saved the silly question,

  

obvious that some design applications do need careful  and consistent torques to achieve a desired fit , but many fitting 

are perfect with common sense   what ever that is .

 

Pete

 

Pete

[Unkel Kunkel]

NASA  not very  impressed by spring washers either, Pete:

 

( You can't pull up on the hard shoulder to fix things up there can you?)

 

"Fastener  Design Manual"   NASA ;March 1990 NASA reference  publication  no. 1228,

 

Author Richard Barnett discussing  spring washers:

 

"In summary, a lock washer of this type is useless"

 

 

Andrew

[Pete Lewis]

reminds me of the Chrysler design standard they imposed on us in the 70s   odd things i remember

 

steering arm  test   park fully loaded against a 12" kerb, apply full lock and drive of at max torque  repeat this 5 times 

 

clutch  park on 1 in 4 hill  fully laden ,,   at max power slide foot off clutch pedal  for 5 hill starts ...

 

            never mentioned the fire !!!

 

           and on a  24ton truck  quite impractical  and Porlock was a days drive and Chobham or Mira too expensive   Ha !

 

              or the old joke about a launderette      Nut,  screws washer and bolts !!!

[Steve C]

Worth mentioning for the newbies also that once Nylocs have been on and off a couple of times they should really be renewed, and always chuck any that have the nylon ring insert coming away.

Know what you mean about torque settings Pete. Experience teaches you when something is nipped up tight enough. Of interest, Alf Francis, Stirling Moss's number one mechanic, even did up cylinder head bolts without a torque wrench. He recounts in his book that he had a spanner cut to the required length which he knew when given the required amount of heft would set them just right.

 

Steve C

[Mjit]

Not arguing about the science of nylocs vs. spring washers the main reason manufacturers switched to nylocs was down to assembly time.  Wacking a nyloc on is a simple task and can often be automated.  Trying to get plain+spring+nut on, especially when you can't see it and are fighting gravity not so much.

 

Of course even nylocs aren't 100% reliable - which is why everything important's drilled and wire-locked in aviation.

[Colin Lindsay]

 

 

 

 

"In summary, a lock washer of this type is useless"

 

 

 

 

And in Wintery, too....