A question about blade play

K

knife saber

Joined
Sep 22, 2002
Messages
400
Hi all,

I've been exposed to a good quantity of knives over the past few years (a friend of mine is a knife dealer) and I've noticed that every folding knife I've played with had a certain amount of side-to-side play. Cheap knives have a lot, and better knives have less, but I've never met a knife I couldn't induce a little side-to-side play into. I've been exposed to almost every brand - Benchmade, Spyderco, Emerson, CRKT, Klotzli, Beretta, Microtech, SOG, and so on. Among customs, I've had the privilege of handling Reese Weiland's work, one or two Crawford pieces, and a few other makers whose names escape me. Even the Sebenzas I've handled have had some small amount of play (invisible to the eye, but discernible by touch). Being of an engineering background, I always accepted this as an inevitability of the tolerances that allow for smooth opening. However, as time passes and I read about every good knife and it's mother having absolutely no side-to-side play, I feel the need to ask: why is everyone conspiring to mess with my head? Or is play up to a certain level simply ignored by knife lovers?
 
If you want to check out a folder that has zero blade play, then look to the CRKT blade lock by Michael Walker. I own one (Don't really use it much as I'm not a fan of AUS-6) but after the moderate work I have done with it, there is still no blade play. I have the Blade Lock 1. I would bet the second would lock up just as nicely.
-KC
 
I think most blades have a tradeoff between no blade play and smooth opening. Compared to my CRKT M-16, my Benchmade 806 has almost indiscernible blade play. If I adjust it to have no play, it becomes hard to open and close.

There is a huge difference in blade play between higher priced, better quality knives (my MB) and cheaper knives (CRKT).
 
Thanks for the replies!

Knifeclerk - I've handled both BladeLock models. I could feel a bit of play (but couldn't see it) on both versions. CRKTs in general I've found to have variable levels of play - some of them will have just barely noticeable play (as on a Spyderco or Benchmade) and some will feel like a generic $5 lockback.

MotoDave - I always felt that play was inevitable on a knife that allowed for a smooth, easy opening action. Yet you'll hear things like "slick opening action" and "zero blade-play" in a review for a single given knife. It's been my experience that those two are mutually exclusive qualities, and I'm wondering if I'm missing something...

What I'm really wondering, I guess, is if "zero blade play" means exactly that, or if there's a bit of play (no pun intended) in the acceptable usage of the phrase.
 
knife saber, are you sure you're feeling blade play, or is the play between the flesh of your fingers and the bone?

I just took out a few of mine and checked them: a Darrell Ralph custom EDC, two Sebenzas, a Strider SnG, a Gunting, a Benchmade 975 that's seen LOTS of hard use, and an Opinel. The only one with any blade movement at all was the Opinel, and that wasn't at the pivot, it was flex in the blade itself.
 
knife saber, you have to adjust the folder to get the best of both worlds. Apply threadlocker to the pivot screw, and slowly tighten the pivot until there is no blade play whatsoever. On a good knife, it will still be smooth. The 806 I have is just right. Supposedly, you can really crank on the pivot of the Sebenza and still keep it smooth.

Where are you feeling for blade play? On some knives the blade itself will flex. It is, after all, a big spring. Try it on a fixed blade.
 
i understand what you're saying. i too have never ever held a folder with absolutely zero blade play. in high-end folders, up/down usually has no play, but there is always some tiny bit of side to side wobble if one adjusts the blade tension to a level where opening is still possible.
the closest thing to zero play that i've handled so far is a BM 733-01. it's almost perfect. almost, but not totally.
i guess you just have to accept that for most people, zero is not zero, but very few :confused:

or we''re just being too picky :D
 
I think Esav hit it. I've got three folders and have checked them extensively for bladeplay. I check them by placing my fingers at the base of the blade and try to wiggle the blade, then I grasp the tip of the blade and do the same. Every now and then I think I feel blade play but then I take a piece of cloth and place it on the blade and try to wiggle the blade again and there is no movement. I assume that what I felt the first time was actually my fingers slipping a little.

Will P. also has a great point about tightening the blade pivot. I really tighten my pivots to the point that no amount of wrist snapping will dislodge the blade from the handle, it takes a definate motion to open. I'm really anal to the extreme about this and about bladeplay in my folders.

My folders include a custom DB Fraley XL Deluge framelock, a BM 630 Skirmish framelock, and a BM 420 Resistor axis lock.
 
I've handled a good number of Sebenzas and never felt blade play in any of them. Just checked my small regular and I can't detect even a hint of blade play in there. I also have to wonder if what your feeling is really blade play, or just the movement of the knife in your hand. I've mistaken that for blade play a number of times myself and always switch to a different, firmer grip and recheck. I currently have 2 Hinderers, 2 JL Williams, a Sebenza and even a recently acquired BM 710 that all have absolutly no blade play (the BM 710 really surprised me, very smooth opener and not a trace of play...it's the first Benchmade I've ever handled that was that way)

Maybe you've just had some bad luck too.
 
Knife Saber, I understand that it seems impossible -- for the blade to swing smoothly, there should be some play, right? Even so, I can't feel any play in most of my folders, and some of them are definitely not high end. For example, I was adjusting the pivot on my BM 551 Griptilian last night, and was amazed how it could be so slick with no play. My Paramilitary, Manix and Sebenza have no play whatsoever in any direction. I wonder if it has something to do with the effect of the lock. I notice on one knife that does have play, that there is far less play when it is locked than when the lock is released and the blade is swinging freely. I suppose the play may also be so microscopic that you just can't feel it.
 
Thanks for all the replies, everyone!

Oh, and just for the record, my name is Andrew (it feels weird to be addressed by a forum handle, especially one as half-assed as mine)

Mr. Benyamin, some knives I just use my fingers for. On nicer knives, I'll do the same. Very often I can feel play as a tactile sensation - a distinct click that I'm fairly sure doesn't originate from my fingers. Sometimes there is an audible noise. If I feel that the loose tolerances of my human hand (What was God thinking? I'm sure his factories are more capable than ours :) ) are interfering with my objectivity I'll put the blade in a padded vise, hold the handle in a normal grip, and lightly move the handle side to side. I keep my eye on the pivot area to watch for motion. Sometimes the stop pin is a handy reference marker, as true play will often cause the blade tang to shift along the stop pin when the blade is locked open. Other times I'll use the gap between the blade and the liners on either side as a quick and dirty scale. When I'm on campus I can use a micrometer. As to mistaking blade flex for play, all I can really say is that I feel confident that I can tell the difference.

Will P. and artsig - I live in NYC, so my pivots are nice and tight. But as long as it's possible for me to open the blade one-handed, without running the risk of spraining my thumb, I can still detect play.

I know I'm being really anal. I really hope I'm not putting anybody out with this obsessive thread of mine. My sincere thanks to everyone for contributing.
 
I have never had any problems with side to side play in my more expensive knives, Sebenza, custom TNT, Microtechs, Nihiser folder etc. The only time that I can feel any amount of play at all is if I really torque the blade, which I really think is unnecessary. I mean if I go and hold the blade out by the tip and the knife as far away from the blade as possible, and then try to snap the blade I can feel a minute amount of play.

I don't really think that checking for blade play involves trying to get the blade to move as hard as you can. The idea is that if it is so loose that it easily moves around the lock probably isn't sound. As long as the blade is locked solidly open, no play, with a resonable amount of pressure it should be fine.
 
Hi Andrew. I think it is a fine topic. There is also a chance that our definitions of blade play are slightly different. As far as being anal, I think my picture is in Webster's for that word! :eek: :)
 
Reminds me of that story about the princess and the pea ;) Made me so nervous I had to take out my Sebenza and play with it - something I wouldn't ordinarily do at work. Well how could I stop there? Out came all my knives. Anyway - there is an almost imperceptible amount of side to side blade play in my MOD CQD MKI and Spyderco Police. There is none in my Sebenza. But I;ll play with them a little longer just to be sure. :D
 
I think yall right about feeling your fingers "play" instead of the blade !

I have checked all my knives and even my old trusty multi tool Leatherman Charge doesnt have any movement at all never mind the Ritter Grip or Sebenza !!

Speaking of which - I cant help but be impressed with say a $50 Spyderco when its quality in certain respects is up there with the best of the customs which cost 5, 10 or even 20 times as much !!
 
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