Recommendation? Pivot washer size relating to pivot pin size.

dano

dano

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Oct 3, 1998
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Simple question for the experts, without going into too much detail. Does the inside diameter of a pivot washer need to match the diameter of the pivot? Example: does a .25 diameter pivot need a washer with a .25 inside diameter? And if that washers ID was much larger than the pivot's diameter, how would the knife function?

TIA
 
I've used washers with slightly oversized holes without any issues. One thing you have to look out for if you're replacing the washers in a liner lock is, particularly if you use oversized washers with a larger outer diameter than stock, make sure the outer circumference of the washer doesn't block the engagement of the lock. Some liner lock knives have locks that are really close to the blade pivots.

Also, if you are using bronze phosphor washers, depending on the thickness of the washer, you can enlarge the hole with a fine round file and some careful filing. The thinnest washers I would do this with are .010" thick. Thinner than that, like .005", is close to paper/foil thickness and too thin to effectively file.


My bronze phosphor washers. I like to keep a large variety of sizes on hand.

Oi5jtPB.jpg
 
Here’s a pic. I think the washer is migrating around the pivot when opening/closing, causing intermittent blade play.
IMG_1128.jpeg
 
dano said:
Here’s a pic. I think the washer is migrating around the pivot when opening/closing, causing intermittent blade play.
View attachment 2596711
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Could you explain what you mean by "blade play"?

I'm having trouble picturing how washer diameter could cause any blade play.
 
When the knife opens/closes, it appears that the washer floats towards the top of the handle and the washer hits the bottom (6 oclock) of the pivot. When this happens, the blade becomes loose, and play seems to be introduced, with it amplified enough that the tip portion of the blade will rub against the non-lock side of the handle.
 
dano said:
When the knife opens/closes, it appears that the washer floats towards the top of the handle and the washer hits the bottom (6 oclock) of the pivot. When this happens, the blade becomes loose, and play seems to be introduced, with it amplified enough that the tip portion of the blade will rub against the non-lock side of the handle.
Click to expand...
I'm not sure of the knife but it seems like it wouldn't cause blade play....but maybe??

If the washers were overly sloppy, it'd be a pretty easy inexpensive way to rule out as a cause by swapping out for some better fitting ones.
 
dano said:
Does the inside diameter of a pivot washer need to match the diameter of the pivot? Example: does a .25 diameter pivot need a washer with a .25 inside diameter? And if that washers ID was much larger than the pivot's diameter, how would the knife function?
Click to expand...
So, is this just one of those "what if" questions or you would realy like to insert a wachers with much larger holes in your knife?
If so I would like to ask why?
 
TheOne45 said:
So, is this just one of those "what if" questions or you would realy like to insert a wachers with much larger holes in your knife?
If so I would like to ask why?
Click to expand...
The opposite. I think the over sized washer is causing excessive blade play. Im going to swap it out with a washer that has the same ID and thickness.
 
dano said:
The opposite. I think the over sized washer is causing excessive blade play. Im going to swap it out with a washer that has the same ID and thickness.
Click to expand...
I would say a larger hole diameter in washers is probably not the cause for a blade play.
I would suspect it has something to do with washers thickness or there could also be some other reason.
Still, you could try washers with proper ID and if this does not help you will know there is something else going wrong.
 
TheOne45 said:
I would say a larger hole diameter in washers is probably not the cause for a blade play.
I would suspect it has something to do with washers thickness or there could also be some other reason.
Still, you could try washers with proper ID and if this does not help you will know there is something else going wrong.
Click to expand...
Good thing you showed up to restate what's already been said.
 
Update. Mic’d the whole package. Backspacer thickness is .193. Blade incl. stock washers is .176. The handles arent parallel when assembled. Thats probably the issue.
 
Skiff blades sells a card that you can measure pivot diameter and bearing/washer thickness, they also sell a large variety of washers and bearings.IMG_8673.jpeg
 
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