Need a thin washer

[Farmer]

This isn't really highly technical, but this was the most appropriate forum.

I need a washer/shim/spacer that is either metal or hard plastic. I've considered making them myself in the waterjet but I don't want to spend $20 on stock and $10 on waterjet time just to make 1 shim.

The outer diameter must be 1-3/8". The inner diameter must be 1-1/4". The thickness should be around 1mm but I am flexible there. There is literally nothing else special about this part.

The problem is I haven't anywhere that sells a shim where the difference between the inner and outer diameter is only 1/8". I've checked McMaster, MSC, Grainger, nothing.

This will not be a load bearing part, I only need this as a spacer/shim.

 

[Howard]

I would try using a retaining ring... What tolerances on the OD, ID, and thickness, and can you stack multiple pieces?

Barring that, you can get some plastic shim stock (make sure the type of plastic matches up with usage and environment) and get a cheap hand punch to stamp out the size you need.

 

[MagnusTheBrewer]

How about slicing a section of tubing?

 

[Howard]

How about slicing a section of tubing?

So smart!

53945K191 on McMaster

 

[Farmer]

Thanks for the responses. The closest thing I've found is a PTFE O-ring of 1/8" width, circular profile. The circular profile isn't ideal but what the hell, worth a shot.

http://www.mcmaster.com/#o-rings/=c2x4kl

The issue is, this part should not be flexible, or should have bulk modulus comparable with aluminum or hard plastic.

Does anyone have experience with PTFE o-rings? The "Durometer" scale says they are about as hard as "shopping cart wheels." I don't know hard those are!

 

[SooperDave]

Copper work? http://www.aircraftspruce.com/catalog/eppages/an900.php

 

[Farmer]

Copper work? http://www.aircraftspruce.com/catalog/eppages/an900.php

Wow, good searching. Didn't see that one. I'll keep it in mind, but I do know copper at those thickness is very pliable/plastic.

 

[MagnusTheBrewer]

What about grinding down a washer with the correct inside diameter? You mount it on a bolt and hold it in place with a nut. Then, you put the bolt in the chuck of a drill and grind down the outside diameter to the size you want.

 

[SooperDave]

What got me there was searching for a banjo bolt gasket. They do make them in aluminum so you could try searching for those.

 

[SooperDave]

What about grinding down a washer with the correct inside diameter? You mount it on a bolt and hold it in place with a nut. Then, you put the bolt in the chuck of a drill and grind down the outside diameter to the size you want.

I was thinking of that but wouldn't you need an a chuck that would take 1.250? It might get out of center if you use a smaller bolt and washers to pinch the part

 

[Farmer]

What about grinding down a washer with the correct inside diameter? You mount it on a bolt and hold it in place with a nut. Then, you put the bolt in the chuck of a drill and grind down the outside diameter to the size you want.

I had a similar idea about building a vice/rig for hold a washer fixed for the lathe, but thought it was too much effort.

 

[MrDudeMan]

I can make you a washer out of UHMW plastic to within .001" (possibly better but can't guarantee it).

 

[MagnusTheBrewer]

I was thinking of that but wouldn't you need an a chuck that would take 1.250? It might get out of center if you use a smaller bolt and washers to pinch the part

You could modify a 3/4" or 1" hole bit to hold the washer then, you could use a regular drill.

 

[MagnusTheBrewer]

I had a similar idea about building a vice/rig for hold a washer fixed for the lathe, but thought it was too much effort.

Never give up! There's always some way to make a tool to make a tool. My grandfather kept his tractor and thresher running through the great depression when there weren't any parts even if you could afford them and no fuel to run them. He made the parts he needed and distilled his own corn to run them.

 

[Howard]

Wow, good searching. Didn't see that one. I'll keep it in mind, but I do know copper at those thickness is very pliable/plastic.

Ring width of 1/8" likely means that the OD will be 2*(1/8) more than the ID, i.e. 1.5".

PTFE tends to run fairly stiff; it is almost impossible to deflect by pinching and does not easily deform with fingernail pressure.

 

[Howard]

How round does this part need to be? We are lacking critical information.

 

[Farmer]

No dimension is critical, the required roundness is not anything particular, the tolerance is not required to be particularly fine.

I have found a solution to this. I purchased some 4" of scrap/leftover mild steel tubing online for a few bucks. It is round. The ID is 1.25" (perfect). The OD is 1.75", but the tubing has significant length (4") and hence can be turned down. I can also cut off at whatever length I desire.

Thanks for all help and ideas. I don't know why I didn't think of this earlier.

 

[Biftheunderstudy]

I would have suggested (based on my experience with making chainmail) using 1/8" wire and a 1-3/8" mandrel to make a coil, then clip them to make rings. This would give you a split ring, alternatively, I think you can buy solid rings with those specs at www.theringlord.com

 

[Puppies04]

I'm not sure i want to click that link Biftheunderstudy

 

[bryanl]

Thin washers like that are used as spacers for gears, often in car transmissions.

 

[Farmer]

Steel pipe turned up today, made the washer:

http://img821.imageshack.us/img821/6167/dsc0158zm.jpg

Thanks all.