Thrust washer

Or, to put it in the requested words of one syllable: A round thing with a hole in it.

Yep, it doesn't even need ball races or rollers or anything of the sort, it could be just a bronze washer.(though they commonly are the former.) So long as it's taking up some of the force that might have a resulting effect on whatever it's sitting on or next to. When it comes to locking handle it can also be used in a different scenario to "bearing forces" to enhance the locking action and make it easier to undo.

Michael W

Edited By Michael Walters on 07/11/2016 09:38:39

Wolfie asked a simple question because he wanted to know the answer - rather than just guessing or making an assumption. This is what we should all be prepared to do as no one knows all the answers even to seemingly simple questions.

My late Father, an expert tool maker, told me to always ask about things or instructions that I did not properly understand. I told him that I feared appearing foolish by asking such questions. He replied that no one worth listening to would think me foolish but I would look really foolish if I guessed the answer and made something wrong wasting valuable materials and time in doing so.

Ask away Wolfie and anyone else who has a seemingly simple question.

Edited By Wolfie on 07/11/2016 13:49:57

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In that context ... the differentiating feature is usually that they are hardened, and ground flat & parallel.

MichaelG.

The chances are no. They may need to be a material with good wear resistance or not liable to rust. Some materials self polish in use other gall up. Galling is what happens when two pieces of material rub together and become sticky enough relative to each other that they effectively cold weld. Some stainless steels are very prone to this. If you make a nice shiny thread on a stainless pipe and decide to test it with a nice shiny threaded female fitting they can stick together to the point where you have to cut off the fitting to get them apart (the answer is to use an anti seize lubricant on the thread first). Phosphor bronze is often used for plain bearing surfaces because it has good properties such as wear resistance, low corrosion and polishes up with use rather than galling up.

**LINK**

Martin

As Martin says no. Thrust washer can be of almost any material, PTFE to ceramic. But the material is chosen for the application, dose it run dry or in an oil bath, is the load low or high and a multitude of other design criteria. If you are replacing an existing washer ensure it is the same material and hardness. When you understand the design rules you may be able to substitute materials. Also ensure that the mating faces are as they should be, any wear on the mating faces may lead to premature failure when you fit a replacement.

Hi Wolfie, some thrust washers have rotating parts on them as has been said, but there are thrust washers that appear to be totally static or in a passive situation but in reality they may have a variable and or vibrating loads on them. If ordinary washers are used in these cases, they are liable to creep and the whole fixture will become loose, even if you are using lock nuts. As MichaelG has pointed out, these thrust washer are likely to be hardened to resist creeping when any variable or vibrating loads are applied to them.

Regards Nick.

OK thanks guys I understand thrust washers now.

I'm working from diagrams that aren't much more than parts lists so all I have is a picture with numbers on, and a list to check the numbers against thus part 86-1234 is a thrust washer.

So the next question is then if part number 86-1234 is missing, how the hell do I find out what it was made of??

Edited By Wolfie on 11/11/2016 16:56:03

Muzzer I'm a truck driver not an engineer, when you can reverse a fully loaded artic into the mill bays at Avonmouth mill and not fall into the dock without asking a truck driver how to do it then come and talk to me

The reason I'm a moderator has nothing to do with engineering and a lot more to do with the fact that I'm good at computers

Edited By Wolfie on 11/11/2016 17:01:10

Hi Wolfie,

What's the bike and what's the washer actually doing (besides thrusting)

Neil

Wolfie, if you were to tell us what bike you were working on or sizes then I am sure someone will know what 86-1234 is. It is more than likely it is or was a commercially made bearing which could be available.

Chris Gunn

As it is now a long time since BSA made motorcycles or parts for them we are into pattern parts for supply, these range from as good or better than original to simply not fit for purpose. Thrust washers on motorcycles can be used for various purposes, some will take a continuous thrust load but others will have more of a shim role where they control any tendency for end float but don't have a continuous load. Often in a gearbox the washer will be bronze and be pegged to stop it rotating against the shell of the gearbox which would wear too quickly. If you have the original part and it is worn or damaged then a fair guess can be made about the original dimensions and material. There will often be some part of the original that is not worn so a dimension can be measured. If it is a steel washer then it will need to be made from a hardenable steel and ground or lapped to size after hardening. A bronze washer will often have a small hole to fit a peg in the casing to prevent the washer rotating and wearing the casing. A bronze washer will often have additional grooves to allow lubrication to reach the thrust areas. If you come up against a particular item that is missing or requires replacing then a picture of the part or the parts list number could help the bike friendly members come up with a useful suggestion. Membership of the relevant owners club can be very useful, they usually have a technical committee member who will know the answer or the right person to ask.

Mike

Edited By Michael Poole on 11/11/2016 18:06:51

Its a BSA C15

The 83-1234 isn't a proper part number, I was just using it for an example.

Wolfie, how about some pictures please? Err I mean of the bike not the thrust washer.....

Edited By John Rudd on 14/11/2016 11:48:28