Spring tension on a slipjoint

[jackknife]

One thing I don't understand is how the half stops are dangerous, could someone explain that to me (seriously just looking for knowledge).
At any rate I do for some reason prefer half stops.

It may be something you may not understand until someday, many years from now. After 25 or 30 years cranking on Bridgeport mills and Hardinge lathes, you develop some Ostio arthritis issues. Or like my wife of almost 50 years, time itself and hereditary genes guide one into some arthritis in the finger joints. This condition is what I have come to call, 'Senior Citizen Fumble Finger Syndrome'.

This is a condition where child proof caps on prescription meds are a pain in the butt to get off, and twist off caps on that cold one from the fridge mean a bottle opener may be needed in a rainy day when you are having a 'bad' day.

The arthritis fumble finger condition means retiring that nice Cross pen you've had for more years than your grown children have been on this earth, and switching to a Pilot G2 for the easy glide writing that is more like an old fountain pen.

It also means abandoning the semi auto pistols because even with a loader, its a pain to load the magazine, so the revolver is king. Just open, insert a live round in every empty hole, when they're all filled, close gun and pull trigger. Old farts love revolvers for many reasons, easy operation is one of them.

Bottom line; the sudden half stop of a sharp blade with the senior citizen fumble fingers or just plain cold/wet/sweaty/bloody/fish slimed hands is not a good thing. Factor in some reflexes slowed by the inevitable march of time, some loss of manual dexterity from that same march, and a stiff spring half stopped pocket knife is an accident waiting to happen at the old folks Bridge club at the Sunny Valley retirement home. It gets the nursing staff all exited.

Hope this helped. Try not to get old, its a bonafide bummer!!!!

 

[brownshoe]

I've been bit by a quick closing half stop slipjoint more than once...guess that makes me a moron, since my arthritis mostly is in my knees It doesn't hit the back of my fingers but my index finger as it goes from full open to half stop. So I guess strong springs and 1/2 stops aren't for arthritic hands and morons like me...

 

[Arathol]

I don't get this- if you can close a knife without half stops without hurting yourself, why can't you close a knife that has halfstops? Same process, but the half stop knife has a pause in the middle....just keep your fingers out of the way in the same manner as when closing the non-halfstop. In other words, don't put your fingers in the path of the blade.....ever.....

 

[Scott J.]

It may be something you may not understand until someday, many years from now. After 25 or 30 years cranking on Bridgeport mills and Hardinge lathes, you develop some Ostio arthritis issues. Or like my wife of almost 50 years, time itself and hereditary genes guide one into some arthritis in the finger joints. This condition is what I have come to call, 'Senior Citizen Fumble Finger Syndrome'.

This is a condition where child proof caps on prescription meds are a pain in the butt to get off, and twist off caps on that cold one from the fridge mean a bottle opener may be needed in a rainy day when you are having a 'bad' day.

The arthritis fumble finger condition means retiring that nice Cross pen you've had for more years than your grown children have been on this earth, and switching to a Pilot G2 for the easy glide writing that is more like an old fountain pen.

It also means abandoning the semi auto pistols because even with a loader, its a pain to load the magazine, so the revolver is king. Just open, insert a live round in every empty hole, when they're all filled, close gun and pull trigger. Old farts love revolvers for many reasons, easy operation is one of them.

Bottom line; the sudden half stop of a sharp blade with the senior citizen fumble fingers or just plain cold/wet/sweaty/bloody/fish slimed hands is not a good thing. Factor in some reflexes slowed by the inevitable march of time, some loss of manual dexterity from that same march, and a stiff spring half stopped pocket knife is an accident waiting to happen at the old folks Bridge club at the Sunny Valley retirement home. It gets the nursing staff all exited.

Hope this helped. Try not to get old, its a bonafide bummer!!!!

I'm already there to some degree. I can't even knock on a door with my knuckles.
Imgur turned my pic upside down??

 

[VCM3]

Stumbling upon this thread this morning . I must add , John has his spring tension carved out very good . Only a few on softer side and even less too firm,with the majority on the money . I now have a small collection of his pocket knives . A great variety of styles and sizes ,unlimited scope of handle covers. The 52100 I have also come to love . I live around salt water ,I don't have a landscaper ,it's me & boy I sweat ! I've never had an issue with rust and I have found the patina ,once you get that nice even gray it hides scratches from use. It hones out to a razor,John's now grinding on a 20" wheel,thin , this steel holds the edge too. Not knives for your velvet lined boxes ,but if you carry and use your custom slipjoint John's knives to me go great with your enthusiasm for our hobby . Thanks for letting me ramble

 

[black mamba]

Carl explained the "danger" of a strongly sprung half-stop knife very well, but I will add that anyone can fumble something once in a while, and with the cam tang the blade stays where it was when fumbled. If the half-stop knife is in between open and half-stop, or between half-stop and closed, then it will "jump" when let go of, and can swipe you. I've been handling knives daily for over 55 years, and I've cut myself exactly twice. Both times when a half-stop blade moved on its' own from spring tension when my grip slipped. Call me a klutz if you like, but I don't think I would have been cut either time if the knives had cam tangs. On a lighter note, I just prefer the smoothness of cam tangs.

 

[RayseM]

I think so too. I mean if they can't operate a simple tool like a pocket knife with a half stop, I'd hate to see them around something more complex... like a can opener.

My "problem" in regards to half stops is that I carry and use other folders and those with half stops always surprise me. My work day carry is most often a non traditional, i.e, an easy one hand opening and closing flipper on bearings. I can open and close wether I am crammed face down in a base cabinet or up on a ladder with one hand holding on to something else. Using a flipper on a daily basis has created muscle memory issues for me. When I draw other folders I have a stall moment when I need to open it bodily with a pinch. Lock backs rather than liner locks slow me down too.

Still, I like carry a range of knives and my weekend or other than work knives are all "traditionals". By Sunday night I don't have any issues opening whatever is in my pocket. Though I do still need to remember when using my Higonokami slip joint that I need to hold onto that bar - or else.

BUT - I never fail to wonder - Why the need for a half stop??? In no way does this improve the usefulness of a knife - IMHO. I have given up on some very nice folders because the half stop always stops me short of the intention to open or close the blade in one motion. Dangerous? I guess that might be hyperbole but I have only nicked myself with 1/2 stopped blades.

If 1/2 stopped blades were the only blades I carried, I would quickly establish a muscle memory that would allow me to open and close without issues but when mixed in with other "styles" - just not worth it. I guess that means that in some instances I am a danger to myself. Otherwise a 7 spring tension is just right.

 

[guy g]

I pulled some slippies out and did my own spring tension check. Definitely Not scientific. Just went thru and saw how they opened for me.
View attachment 1400562Top left.. Case 1980 riggers knife 6246LRSS(if I couldn't pinch it, I'd never get it open) Case 6207SS med trapper( difficult with a hard half stop )
The next group ALL have a nice solid feel to them. I would guess they are described as Medium pull... 94OT, 108OT, Old Frost Cutlery( made in Japan) . Top right.. Buck 301Rosewood, 301 stock, 303(assembled in Mexico ) 303 (made in China) 373( 2007 China)
Next is 303 poly pearl( Walmart) it has a weak spring on the main blade and the rest are fine.
A finally the Smoothist slip I own is the Lone Wolf City Knife(made in Italy) smooth pull with a nice half stop.
I draw no conclusion as to what is best, but it was fun to go thru and check knives out.

 

[JohnDF]

I hope everybody realizes that my "can opener" jab was just tongue-in-cheek.
I realize the day may come where I will prefer a knife without a half stop, seems inevitable.
If it gets so bad that I have troubles opening Traditional knives, I'll simply move back to Moderns... they are easy.
It's all about using the right tool for the job and your abilities. Nobody's forcing anybody to suffer strong springs and half stops.

 

[GaiusJulius]

I like half stops because they’re fun. Pull!-—Snick! —-Thwack!

They’re less efficient than cam tangs, but they afford more mechanical interaction with the knife.

I would not, however, pass on a knife if it did not have half stops.

I do, however, understand that the half stop construction definitely means a knife blade that will move “on its own” for much of its travel. Doesn’t bother me, but my dear wife don’t touch any of my slipjoints. She’s scared of them. Grabs an Opinel or a fixed blade every time.

 

[GE Jr]

I find that my like/tolerance for pull strength can go up or down proportionally to blade size...most times. For instance; the pull on the pen blade on my '60s Case Barlow is so stiff that I need to change from nail nick to pinch grip at half-stop when opening. Pinching a small blade like that isn't usually an issue, but combining the force needed with the fact that thumb & forefinger can easily get wrapped around the edge, can lead to a bite. That knife pretty much stays in the drawer.

 

[afishhunter]

I find that my like/tolerance for pull strength can go up or down proportionally to blade size...most times. For instance; the pull on the pen blade on my '60s Case Barlow is so stiff that I need to change from nail nick to pinch grip at half-stop when opening. Pinching a small blade like that isn't usually an issue, but combining the force needed with the fact that thumb & forefinger can easily get wrapped around the edge, can lead to a bite. That knife pretty much stays in the drawer.

I've noticed on the very few 60 plus year old slipjoints I own, that those with a hard or stiff pull of call it "7 plus" tend to be less used than those with a easy pull of between 4 and 5.5 to 6.
Suggesting that (on average) "back in the day" a knife with a light to moderate pull of between a "4" and "6" was more likely to be used than a knife with a "nail breaker" pull.
The few 60 plus year old slipjoints I have with a heavy pull must have spent most of their time in a socks n' undies drawer or something, before I got them.
(they currently reside in a wood cigar box.)

 

[jackknife]

I've noticed on the very few 60 plus year old slipjoints I own, that those with a hard or stiff pull of call it "7 plus" tend to be less used than those with a easy pull of between 4 and 5.5 to 6.
Suggesting that (on average) "back in the day" a knife with a light to moderate pull of between a "4" and "6" was more likely to be used than a knife with a "nail breaker" pull.
The few 60 plus year old slipjoints I have with a heavy pull must have spent most of their time in a socks n' undies drawer or something, before I got them.
(they currently reside in a wood cigar box.)

I too have noticed something similar, in general. I've seen some old pocket knives that were worn down to sharpened toothpicks that had very easy pulls.

 

[GaiusJulius]

Most men “back in the day” probably bought one knife and carried and used it until it either wore out or got lost. Then they bought a new one and repeated. They might have used their knives far more than we do (or not. It’s hard to say.) but they probably were not “connoisseurs” in the way that most of us are. So it stands to reason they’d like “approachable” pulls, not the more acquired taste of nail-breakers with bear-trap springs.

 

[afishhunter]

Most men “back in the day” probably bought one knife and carried and used it until it either wore out or got lost. Then they bought a new one and repeated. They might have used their knives far more than we do (or not. It’s hard to say.) but they probably were not “connoisseurs” in the way that most of us are. So it stands to reason they’d like “approachable” pulls, not the more acquired taste of nail-breakers with bear-trap springs.

I think on average they used their knives a lot harder than most would even dream of today.
I read somewhere long ago, (confirmed by grand parents, (maternal) great grand father, and (maternal great-great grand mother) that when they were young,) a quality knife (pocket knife or kitchen/woods fixed blade) was expected to last two or three years before it was "used up".

 

[GaiusJulius]

I think on average they used their knives a lot harder than most would even dream of today.
I read somewhere long ago, (confirmed by grand parents, (maternal) great grand father, and (maternal great-great grand mother) that when they were young,) a quality knife (pocket knife or kitchen/woods fixed blade) was expected to last two or three years before it was "used up".

I read that 2-3 year figure once. For some reason I was thinking it was an estimate from a knife manufacturer about longevity, and there was some thought that it probably included loss, accident, simple breakage, etc. Even so, at least by the anecdotal evidence of my own family, it was a wildly optimistic estimate (if drawn up to forecast sales.)

My dad was a blue collar carpenter and mechanic, and he carried the same pair of stockmen from circa 1970-2000. One he bought and one was a partial payment for some work done. He also had a 1980s era small Buck pen, which he didn’t carry because it had a broken backspring.

My grandpa was a farm boy turned cook, and his trio of little serpentine pens, one of which he carried daily, were probably procured sometime in the 30s-50s, carried through the 90s. They’re still in (well worn) functional condition. Maybe my family was just very careful, but I doubt they were that dramatically dissimilar to the majority of men who carried these kinds of knives.

I have no doubt that someone who lived on a farm or spent a lot of time in the woods might go through more, just from sharpening if nothing else. But I bet they didn’t fondle more then a couple dozen knives in their lives. I have a pretty small collection by knife nut standards and I still bet I could conjure up 50 without trying too hard.

 

[JB in SC]

My Bose knives are very smooth openers with a medium pull of about 5. They’re a tad easier to open to half stop. Reese builds a fine knife....

 

[jackknife]

I read that 2-3 year figure once. For some reason I was thinking it was an estimate from a knife manufacturer about longevity, and there was some thought that it probably included loss, accident, simple breakage, etc.

You're 100% correct, Gaius. It was an old article that had a study done by Remington in the 1930's. Remington did a study based on their knife customers about how long they kept a knife in service before buying a new one. It was surprisingly short. A few years was all a pocket knife was expected to last.

Quite an eye opening read. Remington's were very expensive pocket knives in that era.

 

[CVamberbonehead]

I like a pull like a Case trapper. Medium firm pull. I want good snap but not nail breakers. I dont worry bout it closing on me because I dont do stupid things (much ) with my knives.