XM-18 nylon washer why?

[Spartan00]

Thanks Gents! Ill just have to try both and see for myself as well! Now excuse me.....for I just broke the tip off of my Shirogorov 110.......

jk

Bro seriously ! You pissed off a witch or voodoo priest or something?

 

[Gideons]

Heh heh.

If you live in the States you have a lot in choice in knife parts sellers with reasonable shipping rates. :thumbup:
For us here in Canada, many USA part sellers have stupid-high shipping prices.

You should be able to find washers of a suitable size, or that wont take too much work to make them fit.

Oh, I feel your pain on that. I sometimes wonder because the rates are so high if they think Canada is on a different continent or something.

 

[Blade and Flame]

I don't have any issues with nylon washers, but I decided to try out some pb washers to see if I could tell a difference. Using the info Blade and Flame provided, I ordered a few sets. I have two 3" XM-18s, so I swapped out the washers on one of the knives.

So far I can't really tell any difference with smoothness, but it may take a little while for the new washers to settle in. I did notice that the pb washers have a smaller window of adjustment between too tight and too loose, which makes sense. Blade centering with the pb washers is dead on, while both blades slightly favored the G-10 side with the nylon washers.

One thing I did with my PB washers, which I feel is really beneficial in getting the best action, is polishing the washers. Polish like Simichrome works great, others use stropping compound, a fine Sharpmaker rod, or even cardboard. The action on my XM-18s is glassy with polished washers.

Also, one side of the washer can have a very mild burr from how they're punched, so having that on the non-blade side is ideal.

 

[victorf]

From manufacturing stand point, synthetic is both cheap and easy to stamp out.

Personally, I have changed out all my knives came with flimsy synthetic washers for the more robust PB. Since I do machine my own. replacement PB washers are always have larger OD than size came with originally, adding surface area for additional support - however small gain it may be. From mechanical stand point, it is a gain, nonetheless.

I posted this in the recent past, end results in smoothness is no less than with the factory teflon and certainly, gained in better blade centering and firmer stability is significant - OP, you responded in the thread:

http://www.bladeforums.com/forums/s...s-a-little-personalized-distinction-stage-one

***

However, case in point, if underlying component design is weak, not much can be gain by changing out PB pivot washers.

Inherent rough finished thin liners shown had an existing warp condition, once disassembled without associated support, along with thin blade stock....resulted mod was done on a mill without inducing any further distortion to the original warp condition:

I don't carry this knife...too flimsy to depend my life on it...being an unique case...did what I could...but serves well.... if looks could kill!!

***

One the other hand, this came with thin liners but true and flat. Already came with PB washers....but I made and increased .015" to the OD, which is maximum extent for all practical intended purpose + a few personal touch:

It, among the few knives in my possession - my favorite and the only one I carry!

My current obsession.....in progress....came with thin blade stock, flat and true thin liners as well...but rock solid at $124...stock PB washers will be replaced with larger OD...so on and so fourth...

These three production Brothers from the same mother also came with PB...no further improvement can be gain - good as they are:

I do have an affinity using PB for knife pivot application and I leave it at that!

 

[mete]

The original Nylatron was nylon filled with MoS2.There have been cases where MoS2 can break down ,form acid and corrode the steel. It isn't common. However there are other Nylatrons filled with other solid lubes. That wouldn't have the problem.
A possible galvanic [different metals] corrosion exists between steel and bronze. Conductive moisture is needed for the reaction.
I don't know how common either problem is in the real world.

 

[brandoak]

Very informative Thank you for the responses!:thumbup:

 

[brandoak]

A good point about using the right size thickness of washers .....Ive drawn a crude and dramatized picture here to show the micro effects that can happen when the washers are to thick causing binding when closed and blade play when open. The same can happen when changing stand off's with to thin of thickness. This can all happen in reverse as well with to thin of washers and to thick of stand offs. A micrometer can chase away headaches like this..

 

[joejeweler]

My only recommendation is to make sure they are quality precision washers so that centering and binding arent an issue. As for the other concern sometimes two different metal compositions sitting next to each other can cause a reaction but I personally haven't seen it happen and if you use a lubricant it shouldnt be an issue. From what I understand rick uses teflon because he finds its the slickest and did side by sides with phospher bronze and preferred the teflons performance. Im still weird and prefer as much metal in my knives as possible.

The only thing I'm wondering with Rick's test as you outline, is that did he give the phosphor bronze washers a fair shake to seat in? (like working the blade up and down 500 to 1000 times?) Without that as part of the test,...the phosphor bronze washers never got a fair shake. Only stands to reason they need to wear in a bit for optimum fit....

How do I know? I just got in a lightly used XM-18 3-1/2", and it somewhat seemed that when locked open and testing the side to side play, I could feel, or maybe sense a bit of compression of the polymer washers?

I was curious, and didn't want to wait to place a small orderorder to find out,...so I reduced a pair of .025" phosphor bronze washers I had as a spare for one of my ZT 0200 folders, and went down to .013",...the same as my particular polymer ones are. It took over a half hour, using a 1/2" drum sander and my Starrett dial caliper to check along the way. Just worked from ONE side as the other side is already flat, and gives a good visual reference along the way. The last .002" was taken off on a coarse (then fine) diamond knife sharpening stone using honing oil.

I can tell you I DID work the blade at well over 500 times, the last 100 or so with full lockup. The result I is the action is S M O O T H, and no hint, feeling, or any sense of mushiness when locked open and looking for side to side slop.

Another reason I opted to try the phosphor bronze washers was because I'd ALWAYS liked the slick flipping action on my ZT 0200, and I'd used Moly paste (molyebdenum disulfide) with a bit of oil to thin it slightly to get there. The moly paste/oil combo is best used where metal to metal surfaces rub together. I found the stock polymer washers never benefited from the moly application.

For those of you who may not know,... Moly paste reduces wear anywhere metal to metal moving surfaces contact such as pivots and on both sides of a metal washer in a quality folder.

This paste greatly extends the service life and help to maintain tight tolerances involved. It's economical too,...I bought a 2 ounce supply of mine from Jim at Air Rifle Headquarters ( http://www.airrifleheadquarters.com/page/page/251484.htm ), and still have 95% of it left after 15 years,... a little goes a long way!

His is a custom mix with a high percentage of moly, and he uses a bit a graphite in the formulation along with other friction reducing additives. Highly recommend this stuff! (and I have no affiliation with the seller)

In the end,...I am really glade I tried the phosphor bronze washers, and I'd recommend giving it a try sometime,...you just might stay with it as I'm planning to do!

cheers,
Joe T

Ti Rod Tactical

 

[PURPLEDC]

The only thing I'm wondering with Rick's test as you outline, is that did he give the phosphor bronze washers a fair shake to seat in? (like working the blade up and down 500 to 1000 times?) Without that as part of the test,...the phosphor bronze washers never got a fair shake. Only stands to reason they need to wear in a bit for optimum fit....

How do I know? I just got in a lightly used XM-18 3-1/2", and it somewhat seemed that when locked open and testing to side to side play, I could feel, or maybe sense a bit of compression of the polymer washers?

I was curious, and didn't want to wait for an order to find out,...so I reduced a pair of .025" phosphor bronze washers I had as a spare for one of my ZT 0200 folders, and went down to .013",...the same as my particular polymer ones are. It took over a half hour, using a 1/2" drum sander and my Starrett dial caliper to check along the way. Just worked from ONE side as the other side is already flat, and gives a good visual reference along the way. The last .002" was taken off on a coarse (then fine) diamond knife sharpening stone using honing oil.

I can tell you I DID work the blade at well over 500 times, the last 100 or so with full lockup. The result I is the action is S M O O T H, and no hint, feeling, or any sense of mushiness when locked open and looking for side to side slop.

Another reason I opted to try the phosphor bronze washers was because I'd ALWAYS liked the slick flipping action on my ZT 0200, and I'd used Moly paste (molybdenum disulfide) with a bit of oil to thin it slightly to get there. The moly paste/oil combo is best used where metal to metal surfaces rub together. I found the stock polymer washers never benefited from the moly application. For those of you who may not know,... Moly paste reduced wear on pivots really well, greatly extending the service live and tight tolerances involved. I bought a 2 ounce supply of mine from Jim at Air Rifle Headquarters ( http://www.airrifleheadquarters.com/page/page/251484.htm ), and still have 95% of it after 15 years,... a little goes a long way! His is a custom mix with a high percentage of moly, and he mentions he uses a bit a graphite in the formulation among other friction reducing additives. Highly recommend this stuff! (and I have no affiliation with the seller)

In the end,...I am really glade I tried the phosphor bronze washers, and I'd recommend giving it a try sometime,...you just might stay with it as I'm planning to do!

cheers,
Joe T

I honestly have no idea what he did as far as evaluating phosphor bronze. Maybe that was the whole point. Not needing to do as much break in but thats just me throwing out a guess.

 

[joejeweler]

But then that begs the question,...if no one was willing to "break in" their brand new car,...we'd all be driving horses! (unless, of course, no one was willing to "break in" the horse,... Ha!

Joe T
Ti Rod Tactical

 

[RevDevil]

Why are people still using and quoting broken photobucket image links? Just wondering.

 

[unwisefool]

The nylon washers work fine, I've opened my xm18 a lot more than 500 times and there is no blade play.

 

[joejeweler]

Well,..one other advantage of the phosphor bronze washers, is that you can tweak them even further with drilling a series of holes to to help retain the lube. This works especially well with the thicker lubes, but I like a good moly paste and machine oil mixture. The moly thicken the oil and is a great wear reducer.

On the side facing the blade, I add a bit of a taper to the holes to maximize the lube holding surface area. I've found I have a much longer maintenance interval when this system is used with phosphor bronze washers, and could never be used with the polymer ones.

Note: This IS a 3-1/2" XM-18 that was originally a flipper model. I converted to non-flipper, and removed the jimping back of the stop pin originally because it was abrading my damaged index "flipping" finger. (I lost 1/2" of the tip when it got tangled in a motorcycle chain in an accident 45 years ago). The frame dip still works as a comfortable thumb rest now.... and oh,...yeah,.... the PB washer was inadvertently placed on the wrong side of the non-lock side liner for the photo.

Regarding the old photobucket images, I guess we're all hopeful they will come to their senses and reinstate the free photo hosting!

 

[99cuts]

I've switched out the Teflon washers for phosphor bronze on both my XM-18s (one flipper, one non-flipper). I much prefer the action of the phosphor bronze washers. With PB, the action feels faster and more fluid to me.

The Teflon washers always felt a little more 'hydraulic' — smooth and very controlled, but, compared to PB, slightly slower.

The dimensions are 1/2" outer diameter, 1/4" inner diameter and .015" thick. They should be less than 50 cents a pair, so if you're interested, it's cheap enough to see which you prefer for yourself.

I should note that some of the smoothest knives I own run nylon or Teflon washers. But on my two 3" XM-18, I much prefer phosphor bronze.

+1, I also switched to aftermarket PB washers and like them better over orig teflon washers.

 

[halden.doerge]

I think they make a notable difference. I've done it on 6 different Hinderers and talked about them all here.

 

[ATJ999]

Some knives that use both, nylon and Bronze have very smooth actions.

 

[whitty]

While I certainly love the dialogue I don't think it is going to change anything. It is like asking Chris Reeve Knives to make a flipper. I just don't see it happening, but you never know!