What are gaps?

kamagong

Gold Member
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Jan 13, 2001
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A forumite recently posted about receiving a Case knife with no gaps. I found that absolutely incredible. All of my production slipjoints have gaps. Granted I have a fairly small collection and I don't have the experience with them that most of my fellow forumites do, but you would think that I would come across at least one or two slips that don't have any. Am I just unlucky?

Or is it a matter of definition? At its most basic, a gap is nothing more than a space between two objects. In this case, gaps pertain to the spaces between the spring, liners, bolsters, and covers. I guess you could also include the transition between covers and bolsters. Each and every production slipjoint that I have seen has gaps, as evidenced when you can see light peeking through the spine. As a result, I don't worry about it much. If I can't fit a piece of 24# paper all the way through, gaps are a non issue to me.

What say you? How do you define gaps? How often do you get a knife without any?

- Christian
 
I figure that if I look up into the knife, I should not be seeing light in between the components of the knife, let alone have a gap that I can slide a piece of note paper into. But that's just my definition.

Carl.
 
'Gaps' are those little slivers of light seen between scales & covers, or scales & backsprings, when holding the knife up to the light. Interestingly, they are what show up today, that mysteriously didn't exist yesterday, and might or might not exist again tomorrow. :D

Seriously, I've never seen a production folding knife that didn't have them to some degree, IF I actually look for them. It's easy to miss them at a quick & cursory glance, and assume the knife is 'perfect' in fit/finish. Then, Lo and Behold, they 'suddenly appear' the next time I look it over.

I have ONE knife, a custom (maker to remain un-named), on which the tolerances between liners and springs are so tight that the blade well actually holds liquid without dripping. I noticed this when flushing it out with some isopropyl alcohol. Poured the alcohol into it, expecting it to run through and drain out, and it just stayed there. That's the 'tightest' knife I've ever seen. Unfortunately, it's so tight that the opening pull is very, very hard (this is why I was attempting to clean it in the first place). Sometimes, a little space is a good thing, in allowing everything to move smoothly.

Agreed, some gaps are egregiously wide, big enough to support a business card, or catch & hold a thumbnail when pressed into them, or worse. But, I don't expect total darkness when holding a knife up to the light. Only takes about a micron of open space to see light (maybe less), and expecting the tolerances to exceed that on each and every single example of a production knife seems ridiculous to me. Sometimes you get 'lucky' though...


David
 
For me, large gaps have been more rare (about 8%) than literally no visible gaps (about 12%), which leaves about 80% of my pocket knives from $6 to $500 that have slight or negligible gaps. Only the big ones bother me, but it is nice to NOT see the light, in this case!
 
I figure that if I look up into the knife, I should not be seeing light in between the components of the knife, let alone have a gap that I can slide a piece of note paper into. But that's just my definition.

Carl.

That's what I'm talking about. I don't have any slipjoints that meet that definition, apart from my three customs. As a result I've loosened my standards a bit. Can't reasonably expect a production knife to compare to one that is made by expert cutlers, one at a time.

The only traditional-esque knife I have that comes close is a Moki lockback. There is some clearance between the lockback spring and the liners, but that seems to be by design since everything else is flush and tight. A remarkable knife really, the closest I've ever seen a production knife come to custom quality.

'Gaps' are those little slivers of light seen between scales & covers, or scales & backsprings, when holding the knife up to the light. Interestingly, they are what show up today, that mysteriously didn't exist yesterday, and might or might not exist again tomorrow. :D

Seriously, I've never seen a production folding knife that didn't have them to some degree, IF I actually look for them. It's easy to miss them at a quick & cursory glance, and assume the knife is 'perfect' in fit/finish. Then, Lo and Behold, they 'suddenly appear' the next time I look it over.

I have ONE knife, a custom (maker to remain un-named), on which the tolerances between liners and springs are so tight that the blade well actually holds liquid without dripping. I noticed this when flushing it out with some isopropyl alcohol. Poured the alcohol into it, expecting it to run through and drain out, and it just stayed there. That's the 'tightest' knife I've ever seen. Unfortunately, it's so tight that the opening pull is very, very hard (this is why I was attempting to clean it in the first place). Sometimes, a little space is a good thing, in allowing everything to move smoothly.

Agreed, some gaps are egregiously wide, big enough to support a business card, or catch & hold a thumbnail when pressed into them, or worse. But, I don't expect total darkness when holding a knife up to the light. Only takes about a micron of open space to see light (maybe less), and expecting the tolerances to exceed that on each and every single example of a production knife seems ridiculous to me. Sometimes you get 'lucky' though...

David

That's how I feel as well.

- Christian
 
If I have to hold the knife up to the light to detect a gap, honestly, that doesn't bother me. That said, only my Cases and Queen/S&Ms show any such gaps, and they're very minor. I can tell from the backside that there's a tiny gap, but they're not big enough to slip a piece of paper through. If they were that big though, I wouldn't be happy.
 
I have many GEC's, some Cases, an S&M, one custom and various others. All show slivers of light. The ones that show the least are my alox saks.
 
If I have to hold the knife up to the light to detect a gap, honestly, that doesn't bother me. That said, only my Cases and Queen/S&Ms show any such gaps, and they're very minor. I can tell from the backside that there's a tiny gap, but they're not big enough to slip a piece of paper through. If they were that big though, I wouldn't be happy.
A piece of paper is about .0035. That's a very little gap.
 
Just done a quick check of the knives that are on my coffee table: Two GECs (no gaps), Maserin (gaps), Boker (gaps), Otter (no gaps), Arthur Wright (gaps), Abram Brooksbank (no gaps), Camillus (no gaps). Unless you can get a thumb-nail in there, the gaps don't bother me too much, but I appreciate the workmanship that goes into a knife where there are none.
 
A few GEC, one case bose (actually holds liquid like OWE mentioned), henckels, Richard Rogers.

Kevin
 
I don't have a definition really, but I know one when I see one. If I have to really look for a gap, then it doesn't have any. If it is easy to see and stands out when you look at the knife, then yes it has gaps. We enthusiasts can be a tough bunch to build a knife for.

Having said that, I have several knives with some gaps. Every knife has to have clearances or it will not function. When does clearance stop being clearance and start being a gap? For me, it is when you can get a dollar bill or piece of paper to slide from the back of the knife into the interior of the knife or it looks like a gap (see above). I don't generally worry about gaps unless they affect the function of a production knife.

Of the ones I own, Case is the biggest offender, but I only have one stockman that has a wobbly blade out of the box. The GEC knives are well made and it shows in smaller gaps/tighter clearances.

You guys are all familiar with my "precious", the amber bone mini copperhead. It has gaps. Oh well, I love it anyway. Enough so, that I have bought four more of that pattern from Case. You folks may have see the blue bone that I carry on Sunday. Guess what, it has gaps too. These gaps do not affect the function of these knives at all. I am happy with them. Now the ruby red White Owl I have is also a single spring, two blade knife, a knife that seems smaller than it actually is. If I very closely examine this knife with a backlight I can see the clearances, but to me, this knife doesn't have gaps. It, too, functions perfectly. Why then don't I prefer it over the mini copperheads? I'm afraid I don't really know the answer to that question.

Ed J
 
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Don't sweat the small stuff.
 
After seeing this thread I took out a handful of my Case knives and looked at them closely. I've got a couple with visible gaps between the backspring and liner, but nothing major. I have more that don't have visible gaps at all but if you look straight at the backspring towards a bright light you can just see a faint bit of light. And I have some that you can't see light through at all, like the Russlock I'm carrying today.

None of mine are wide enough to slide a piece of paper through, but to be honest I only looked at about 10 knives and of that I'd say 2 had gaps that were noticeable just by looking at the knives without using a back light. Those two work just fine and since they are carry knives I'm not worried about them being museum-quality in their fit an finish.
 
I figure that if I look up into the knife, I should not be seeing light in between the components of the knife, let alone have a gap that I can slide a piece of note paper into. But that's just my definition.

Carl.
Same here; I don't like to be able to see light coming through my pocket knife... the parts should fit together snugly.
 
I've got knives with gaps you could pitch a house cat through. And I have some, like the GEC jack I am carrying today, which has no visible gaps either in the spring/liner joint or the handle/bolster joint. I have tried to see light through this one and just cannot see anything at all. The 68 owl that I adore ~does~ have a slight gap on one side of the spring but it is very small and you have to play with angle a bit to finally see it.

Most of the GEC knives I own have little to no gaps. A couple of my Case knives have no visible gaps and the rest have small ones. My queen knives are probably 50/50 if you count gaps between the handle and bolster that adds in most of those with no metal gaps. The Bokers I own have either gaps in the handle/bolster or in the liner/spring joints.

That's how mine stack up Christian.

Will
 
Thanks for sharing your thoughts all. It's as I suspected; there is no general consensus on what constitutes a gap. It seems it is more a matter of what the end user can, or can't live with.

- Christian
 
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