Unlocking a Lock Washer

I'm not even sure what the offending item is actually called. However, it is a washer about 10 thou thick and 14mm in diameter, with four tabs on the inner edge that are sprung upwards and engage in a groove on a shaft about 6mm diameter so as to lock it to a large metal disk. It's actually part of a cafetierre and has a stripped thread. The intention is to make a new part and replace it, preferably using the same lock washer.

So far I've tried sliding dressmaker's pins under the tabs in the hope that this will force them apart enough to free the washer. The first pin works fine but later ones will only go below the washer rather than above it when they emerge from the other tabs, as the washer is distorted by the first pin.

Any bright ideas?

You will be very lucky if you manage to re-use that washer … they are, as you have no-doubt already realised, designed to go on, and stay on.

I would concentrate on getting it off, whilst causing minimal damage to the other components.

MichaelG.

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It may be a special, but in principle it’s like these:

https://www.springmasters.com/push-on-fasteners/

Edited By Michael Gilligan on 17/11/2022 22:04:59

I believe the official generic name for these never to be sufficiently cursed things is "spire - nut".

I have shifted the big ones using a teeny pair of pliers to bend the tabs back one at a time to clear the groove and packing the washer up just enough, in line with the tab, to stop it springing back down. Once over the groove it could be walked off but the shaft wasn't pretty afterwards.

Creative swearing was involved!

Things got re-engineered on assembly.

The smaller ones on 3 - 4 mm or imperial equivalent shafts can be brute force twisted off using a screwdriver underneath but that doesn't work on the bigger ones.

With reference to Michaels link the multiple tab push on style can be inverted by careful levering so the clip can be worked off. Sometimes the quicklocks can be inverted too, most likely if on a plain shaft rather than in a groove. Right size starlock on right size shaft with groove are there for life.

Clive

Edited By Clive Foster on 17/11/2022 22:13:27

That "washer" isn't meant to be taken out.
You could clamp the part in a lathe and turn that washer in pieces.
Use a Dremel kind of tool to grind the washer in pieces.

The outer top ring is probably pressed in. Maybe an inner bearing puller could pull it out.

It looks like a "Star Lock Washer".

Removing a star lock washer

Edited By Huub on 17/11/2022 22:14:35

Many thanks gentlemen. Is there a speed record for replies I wonder? I'll hold fire for a while in case someone with magic powers comes up with a solution but I can see my next step will be trying to buy a single StarLock push on fastener after butchering the current one, and being told there's a £25 minimum order (+postage and packing...).

Star lock washers are available singley on Ebay from £1.25

Other sizes than the one I selected to get a link are available from drop-down menus on the page linked to.

Nigel B.

Thanks, mgnbuk. I'd done a bit of sleuthing too and found the same site, so my normal cynicism for once was unfounded.

These items are called "external shaft retainer clips / washers / rings" - just mentioning it for your part search.

+1 on cutting the old one with a Dremel grinding wheel or similar. If you try pick or lever tools usually so much damage is done to the adjacent parts or the shaft that even with a new ring the repair isn't good. Cutting gets them off with no trauma to adjacent bits.

A link to a major US based suppliers' range for info only is below.

https://www.mcmaster.com/shaft-retainers/retaining-ring-type~external/push-on-external-retaining-rings-6/

Edited By Jeff Dayman on 17/11/2022 23:59:53

Edited By Jeff Dayman on 18/11/2022 00:00:13

Can you wrap a piece of thin brass shim around the shaft and slide it down to the star washer then pry one leaf of the star open at a time and slide the shim in then slide the whole lot off as one?

These washers are intended as an easy to fit, non reuseable item.

Almost always, removal requires it to be damaged beyond reuse, plus damage to the shaft

Cut with a dremel, and replace (see below ) would be my choice.

In UK, one brand is "Salterfix", but no doubt, places like Machine Mart, Toolstation, or Screwfix will sell you a box containing about 100 in different sizes!

In the past, faced with this, where possible, I have drilled the shaft and fitted a washer retained by a split pin.

That old fashioned arrangement allows disassembly and reassembly without problems.

Howard

You say the washer is part of a cafetierre, is this part immersed in the coffee, if so is probably made out of some form of stainless so replacement should be a likewise material. Not sure how ordinary steel or zinc plated steel would hold up in that environment, probably not good to dissolve zinc coating into your coffee although according to doom merchants coffee is rated as toxic anyway. Dave W

If the shaft has a groove to retain the spire clip it must be a luxury item. Circlips saved threads, spire fix saved having a groove.

Regards Ian.

The last one I had to remove the outside edges were lifted up so the washer was effectively reversed then prised off.Oh and replaced with a thin washer and circlip

Edited By bernard towers on 18/11/2022 10:26:33

Circlip, it's a pretty basic cafetierre, but the shaft is grooved, which rules out Hopper's cunning plan. I'm away for a while now but it sounds like a bit of light Dremelling will do the trick when I'm home again.

Samsaranda, yes it's immersed in the coffee but I have in mind to make the replacement from brass. Those small conical pots used to make real Turkish coffee are brass; it's strong stuff and it doesn't seem to kill many of the Turks.

We have a box of Starlock washers at the museum, a range of sizes, but they are spring steel zinc plated, you need stainless steel. You would need four custom made spikes to try to get the ears to move outwards as they are pressing into the end of the shaft. A difficult task, a lot of luck required as well as skill.

If planning to make a new part anyway, consider drilling or turning the part away to release the washer.

We used to refer to them as "Marriage Clips ", there till death do us part !, no second rounds !

This website might have what you need. I've bought from them in the past.

spring fasteners

Dave

Stainless steel starlock washers are available on ebay, by searching for "stainless starlock washers", the size will be the shaft diameter.