Pivot Washer Size Importance

[MBG]

Does anyone think washer (or bearing) size matters? I'm talking about diameter more than thickness.

My assumptions are that it affects:
-stability
-strength
-smoothness

The only positive I can think of for a smaller washer is lower friction.

I have always appreciated large washers like on CRKs and the Benchmade Adamas.

The thing that really prompted this question is that I just got an M4 Bailout and the washers are tiny. I'm pretty sure they just reused the same washers for the Bugout, which makes sense for the Bugout, but for the Bailout, I would like a little more material. I think Griptilian washers would be perfect for this knife, but I don't know if it matters enough to try swapping them out.

I decided to compare washer sizes on a few knives that seem comparable. Endura/Delica washers seem comparable to the bugout/bailout. PM2 washers seem equivalent to Griptilian washers. Hinderer XM-18 washers (triway) are anemic in comparison to CRK washers, they are even smaller than Griptilian washers.

This begs the question, does Rick Hinderer think it doesn't matter? He knows way more than I do, that is for sure. Maybe he makes up for it with the blade stops? A smaller washer is required due to frame-lock design and tri-way? I suppose the only way to have bigger washers on the XM would be to use CRK style washers.

Am I just overthinking this?

 

[johnnytoxin]

My experience has been that larger diameter washers provide more lateral stability (less likely to have side to side play). I’ve owned very smooth knives with both small and large diameter washers so I don’t think the larger washers provide any advantage there. I don’t have any experience with bearings so I’m not sure if the same goes for them.

 

[K.O.D.]

With bearing pivot knives, a larger circumference cage would most likely not work, as they are fitted more exactly into the frame. Increased thickness would also cause issues.

Maybe if you expanded the pivot area of the frame larger washers might work, but I know nothing of machining.

 

[The Aflac Duck]

The detent and lockbar have a lot more to do with smoothness than washers or bearings. Larger diameter washers would in theory be stronger since they dampen the load across a larger area, but we are talking about a folding knife, not components of a space ship. It’s all overthinking, IMO.

 

[Alberta Ed]

I wouldn't attempt to outguess the engineers who design knives. If it ain't broke, don't fix it.

 

[killgar]

I see three possibilities-

1. After a thorough evaluation of the design requirements and engineering involved they're using the best washers for the knife.

2. They're saving money by using washers they already have in stock that will work in the knife.

3. They're saving money by using smaller diameter washers which are cheaper because they're made of less metal.

I've always preferred the largest diameter washers that will fit, but it's really just a psychological thing. Larger diameter washers provide more support for the blade like Johnnytoxin mentioned, but in all honesty I never needed that additional support.

It seems to me that the smaller the diameter the washer is, the less friction there will be on the blade during opening and closing. Smaller diameter washers might make for a smoother, faster action, but again, I've never had any complaints about the action with my folders with larger washers.

As far as "overthinking", heck, we're on a knife forum, it's safe to say most of what goes on here qualifies as "overthinking". And overthinking knives makes being a knife enthusiast all the more enjoyable .

 

[ferider]

This begs the question, does Rick Hinderer think it doesn't matter? He knows way more than I do, that is for sure. Maybe he makes up for it with the blade stops? A smaller washer is required due to frame-lock design and tri-way? I suppose the only way to have bigger washers on the XM would be to use CRK style washers.

Reg. Hinderer: (1) washer size is less important as the two thumbstuds stabilize the open blade in the third dimension. (2) on the lock-side, washer size is limited by the gap of the lock. Some people put larger washers there, but I think seeing part of the washer behind the lock is kind of ugly.

That being said, my Fulltrack (same tri-way bearings as the XM-18) that runs on washers does have larger ones that I put in there.

I've thought about this when cleaning some Spydercos: some of them have diminutive washers for their size, like the Police 4, or the Chinook 3. Then again, that's what you pay for "flickability" I guess.

Roland.

 

[jiggyfly16]

Reg. Hinderer: (1) washer size is less important as the two thumbstuds stabilize the open blade in the third dimension. (2) on the lock-side, washer size is limited by the gap of the lock. Some people put larger washers there, but I think seeing part of the washer behind the lock is kind of ugly.

That being said, my Fulltrack (same tri-way bearings as the XM-18) that runs on washers does have larger ones that I put in there.

I've thought about this when cleaning some Spydercos: some of them have diminutive washers for their size, like the Police 4, or the Chinook 3. Then again, that's what you pay for "flickability" I guess.

Roland.

I think you kind of have to put smaller diameter washers in with the delica and Chinook since they are lockbacks and the washer has to sit below the locking notch on the blade.