Using washers under nuts

[garyboy]

You'd think so wouldn't you but the flanged nut spreads the load much better and doesn't distort like a washer does, the proof is in the pudding and I see far less damage from a flanged nut than a washer on regularly removed nuts. A classic is the rear wheel nut on an Aluminium swinging arm, I bought a new oem flanged nut for my KTM, my mate fitted a nut and washer, it wasn't long before his swinging arm looked a mess with the edges of the slot starting to burr over etc, an extreme example as if he'd used a new washer each time there wouldn't have been as much damage but my swinging arm still looked fresh and flat with no marks.

Steve

mmm ... thanks for that .. very counter-intuitive ... I will give preference and precedence to flanged nuts from now on

[bill_qaz]

and indeed throwing away the torque wrench altogether and buying huge calipers to actualy measure the the bolt stretch!!

The manual for our old Leyland buses gives a measurement for bolt stretch instead of a torque or angle (big end cap bolts)

I much prefer the flanged bolts and nuts, they dont make a mess of aluminium (or other soft surfaces) like a washer does.

Steve

The idea came from AEC part of the Leyland group, the big end bolt had machined surfaces top and bottom and was bench tightened until a specIfield stretch, measured with micrometer then centre pop bolt and two casalationns on the nut. On assembly they lined up when hand tight then the next revolution was correct tightness. Each nut was numbered 1,2,3 etc starting at number one con rod with all odd number one side and even on the other, great idea.

[Hugh]

Greetings,

Some bolts/studs/nuts etc are meant to surface corrode so that they don't come loose over time, vibration, expansion/contraction, etc. Other fastenings use stretch measurement, some degree settings, some locking wire, split pins, shaped washers, etc.

Blue printing. Thinking about torque settings, I recall fitting propellors to aircraft.

We used a 'large' measured twin winged length splined socket bar, connected to length of steel rope which was connected to a specified weight ( a block of concrete) and the prop rotated turned until the bar stopped passing 90º, make a thin pencil mark across the boss and nut, make a second mark a set distance from the first boss mark, remove the rope and adjust (beat) the bar with a 'Winchester screwdriver' until the marks line up, fit a spline lock plate (if the lugs did not line up smack the bar to the next cut out). Sounds brutal but I never knew of one falling off

If the manufacturers specify a product then that's what should be used, why, because thousands of hours testing, money and examining - one duff or incorrect washer and the thing falls out of the sky

TTFN

Hugh

[garyboy]

Greetings,

Some bolts/studs/nuts etc are meant to surface corrode so that they don't come loose over time, vibration, expansion/contraction, etc. Other fastenings use stretch measurement, some degree settings, some locking wire, split pins, shaped washers, etc.

Blue printing. Thinking about torque settings, I recall fitting propellors to aircraft.

We used a 'large' measured twin winged length splined socket bar, connected to length of steel rope which was connected to a specified weight ( a block of concrete) and the prop rotated turned until the bar stopped passing 90º, make a thin pencil mark across the boss and nut, make a second mark a set distance from the first boss mark, remove the rope and adjust (beat) the bar with a 'Winchester screwdriver' until the marks line up, fit a spline lock plate (if the lugs did not line up smack the bar to the next cut out). Sounds brutal but I never knew of one falling off

If the manufacturers specify a product then that's what should be used, why, because thousands of hours testing, money and examining - one duff or incorrect washer and the thing falls out of the sky

TTFN

Hugh

if only modern air planes were made and tested so thoroughly. (737)
I had no idea this sort of stretch testing went on.

rust .. the same in building construction .. re bar is preferred to be rusty for grip within the concrete.
but why the engineers/designers place the bars 2" from the outside? .. will obviously lead to excessive rust, as only 9" of concrete is `waterproof` .. despite that position being the most structurally effective.

[Dark Knight]

i have been wondering about this for a while now.
i was always led to believe that washers were always a good thing ..anywhere and everywhere.
but that badly fitting washers can mess things up a bit.
I always felt that the use of washers lessened the torque strength of a bold/screw, but never thought of the rough -surface/ friction, effect, which would dissipate the original torque at every surface.
I notice that these days bikes don't seem to have a large washer under the big nut at the rear axle.

I have noticed that there is a big difference if, eg, you tighten up the nut, as opposed to the bold head... especially at the rear axle and at the rear chain cog nuts.

I had my chain tightened at my local mechanic, as a favour while changing a tyre. I noticed that the assistant tightened from the bold head side .... when i got home i tightened up the axle from the nut side ... loads of movement .. by hand with a small leverage hand spanner, 27mm. ... doh..

As regards the rear wheel/axle arrangement.
I always apply the 80 ftlbs to the nut while holding the bolt end with a spanner.
Because I am using grease on the threads, the washer remains static while the nut turns to provide the rquired tension.
In reality of course it is provinding more than the intended tension because of using grease, most service manuals would not recommend using grease.
Better safe than sorry, assuming that we have a quality rear wheel bolt.

[garyboy]

i have been wondering about this for a while now.
i was always led to believe that washers were always a good thing ..anywhere and everywhere.
but that badly fitting washers can mess things up a bit.
I always felt that the use of washers lessened the torque strength of a bold/screw, but never thought of the rough -surface/ friction, effect, which would dissipate the original torque at every surface.
I notice that these days bikes don't seem to have a large washer under the big nut at the rear axle.

I have noticed that there is a big difference if, eg, you tighten up the nut, as opposed to the bold head... especially at the rear axle and at the rear chain cog nuts.

I had my chain tightened at my local mechanic, as a favour while changing a tyre. I noticed that the assistant tightened from the bold head side .... when i got home i tightened up the axle from the nut side ... loads of movement .. by hand with a small leverage hand spanner, 27mm. ... doh..

As regards the rear wheel/axle arrangement.
I always apply the 80 ftlbs to the nut while holding the bolt end with a spanner.
Because I am using grease on the threads, the washer remains static while the nut turns to provide the rquired tension.
In reality of course it is provinding more than the intended tension because of using grease, most service manuals would not recommend using grease.
Better safe than sorry, assuming that we have a quality rear wheel bolt.

hmm .. that's interesting .. so using grease will give a larger torque to the axle bolt?
you would think that this should be in the spec . tightening torque .. with or without grease ..
perhaps there is a smaller difference that we assume?

I am going to Halfords tomorrow ,.. to get a 27mm socket £7.50 for the long reach one .. to use with my Halfords excellent big 1/2 " torque wrench .. i will look for some copper grease to .. and get my tight hand into ma wallet lol . .. how will we manage when our local halfords shuts down in March? .. dont think its nation wide?

I dont understand how i lost such an important nut ... lucky i got a scrote then eh?

O .. btw .. i got my honda chain set today ... great ride over the bwlch and rhigos, in the rain and mist ... dry as a bone tho .. yay..

[Oop North John]

i have been wondering about this for a while now.
i was always led to believe that washers were always a good thing ..anywhere and everywhere.
but that badly fitting washers can mess things up a bit.
I always felt that the use of washers lessened the torque strength of a bold/screw, but never thought of the rough -surface/ friction, effect, which would dissipate the original torque at every surface.
I notice that these days bikes don't seem to have a large washer under the big nut at the rear axle.

I have noticed that there is a big difference if, eg, you tighten up the nut, as opposed to the bold head... especially at the rear axle and at the rear chain cog nuts.

I had my chain tightened at my local mechanic, as a favour while changing a tyre. I noticed that the assistant tightened from the bold head side .... when i got home i tightened up the axle from the nut side ... loads of movement .. by hand with a small leverage hand spanner, 27mm. ... doh..

As regards the rear wheel/axle arrangement.
I always apply the 80 ftlbs to the nut while holding the bolt end with a spanner.
Because I am using grease on the threads, the washer remains static while the nut turns to provide the rquired tension.
In reality of course it is provinding more than the intended tension because of using grease, most service manuals would not recommend using grease.
Better safe than sorry, assuming that we have a quality rear wheel bolt.

hmm .. that's interesting .. so using grease will give a larger torque to the axle bolt?
you would think that this should be in the spec . tightening torque .. with or without grease ..

Assume that it's a dry thread unless they quote a greased one. So many types of grease that you'd probably need a book for the torque loading options for each type

Run down torque, ie the force needed to turn the nut on the bolt is part of the final torque figure. It assumes that you don't grease the bolt, unless required to and is in a clean and decent condition. Think of how difficult it is to undo a corroded bolt, but how much easier it is to do it back up, as the threads have been cleaned up by the nuts removal.