Half-stop?

ron_m80

ron_m80

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Mar 1, 2009
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What is the reason for a half-stop on a traditional slip-joint folder?

Thank you.
 
Safety. It gives you time to make sure your fingers are out of the way before the blade snaps shut on them.

Actually, that's just a guess. Some have them, some don't. By and large, I prefer those that do have half-stops for the safety factor.
 
Many people will tell you that it's for safety and all that, but really, originally, it had to do more with ease of construction and reliability. For a very long time, blades - particularly the tangs - were filed to match hardened patterns. It's a heck of a lot easier to file a square tang profile (the half stop is the flat end of the tang) than a rounded one (actually the profile isn't quite square, but we'll ignore that for now). Also, for a long time the old mark of quality construction was the "clean and square" joint - basically the square tang was matched to a square bolster, essentially filling the joint, even when closed. This meant that if you dropped your knife in the dirt, the dirt didn't get into and around the joint to foul up the mechanism. (Remington "discovered" this early last century. :rolleyes: )

A square tang is largely self cleaning -- the corners sweep debris either toward the end of the knife or back into the body - either way, the debris gets moved out from under the tang/joint mechanism where it can then be removed. Properly cleaning up an old, gunked up knife and getting all the crud out of the mechanism is a lot easier with one that has square tangs.

Also, a square tang causes less wear and tear on the spring over time - assuming the corners of the square tang were rounded a tiny bit in construction. The corners sweep back and forth along a length of the spring in operation. spreading the wear evenly along that length. A round or cam end tang concentrates the wear in a much smaller area of the spring - becoming a problem when proper maintenance and oiling is neglected.
 
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Neat, thanks. I always thought it was a finger preservation system as well.
 
zerogee said:
Many people will tell you that it's for safety and all that, but really, originally, it had to do more with ease of construction and reliability. For a very long time, blades - particularly the tangs - were filed to match hardened patterns. It's a heck of a lot easier to file a square tang profile (the half stop is the flat end of the tang) than a rounded one (actually the profile isn't quite square, but we'll ignore that for now). Also, for a long time the old mark of quality construction was the "clean and square" joint - basically the square tang was matched to a square bolster, essentially filling the joint, even when closed. This meant that if you dropped your knife in the dirt, the dirt didn't get into and around the joint to foul up the mechanism. (Remington "discovered" this early last century. :rolleyes: )

A square tang is largely self cleaning -- the corners sweep debris either toward the end of the knife or back into the body - either way, the debris gets moved out from under the tang/joint mechanism where it can then be removed. Properly cleaning up an old, gunked up knife and getting all the crud out of the mechanism is a lot easier with one that has square tangs.

Also, a square tang causes less wear and tear on the spring over time - assuming the corners of the square tang were rounded a tiny bit in construction. The corners sweep back and forth along a length of the spring in operation. spreading the wear evenly along that length. A round or cam end tang concentrates the wear in a much smaller area of the spring - becoming a problem when proper maintenance and oiling is neglected.
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The most sensible explanation I've heard in a long time!!:thumbup:
I knew I loved half-stops, now I know why!!;):D
 
I am feeling like my education on slipjoints has evolved from a slime mold to a more complex organism such as an amoeba! Thanks for that half stop info. It makes perfect sense, and I thought I liked it because it was like a bonus mini snap during the opening and shutting process.
 
Nice explanation, Dwight. I can say from experience that half-stops aren't more safe than cam-end knives :eek: Half-stops will get ya faster and harder than cam-ends. :D And as far as construction goes, half-stops are way harder to execute correctly!

I have a love/hate relationship with half-stops. :p
 
I always figured that it was a sinister ploy to make sure that it REALLY got you if you happened to have your finger in the way by mistake. :eek:
 
KnifeHead said:
Nice explanation, Dwight. I can say from experience that half-stops aren't more safe than cam-end knives :eek: Half-stops will get ya faster and harder than cam-ends. :D And as far as construction goes, half-stops are way harder to execute correctly!

I have a love/hate relationship with half-stops. :p
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This is true -- I've been bitten by any number of knives with half-stops, with them snapping down and nipping whatever is too close (with the stronger ones being more dangerous, since I'm more likely to be holding the handle wrong in an effort to crank the blade closed past the half-stop -- and of course, the strong ones can then really put the bite on ya). I've never gotten bitten by a cam-end knife -- by starting their snap much closer to the handle, I've already naturally moved everything out of the way (also, I'm not working to crank the blade past the half-stop to close it).

Half-stops have many things going for them -- safety really isn't one of them. I've also gotten many little shallow surface slices or scoops out of my fingertips from sharp narrow half-stop blades with firm or stronger action, since my fingertips surround the narrow blade as I pull it open past the half-stop.

I do wonder if the old cutlers (meaning pre-1800's) worried much about the spring being flat in all three positions? There's not really any functional reason other than neatness and our general OCD about such things to have the spring totally flat at half-stop -- close would be plenty functionally - just to minimize spring loading (in fact, having the spring a bit sunk at half-stop would actually better minimize loading, technically).
 
I agree that close is good enough. Only problem...it's that rascally Old Dog that raised the bar and keeps us lookin for that +/- .000" difference in liner and spring height in all three positions...I blame him!
 
Well, it's not really the Old Dog's fault -- the great old Sheffield and American cutlers had already set that bar in position. :eek: After all, a true craftsman can't abide being out-finessed.
 
I agree with Kerry and everyone else on the strong spring coming off half stop is more likely to get you. I can also see less wear with the larger surface of the half stop,--however we have spring rise twice coming around the corners. In a perfect world with smooth corner radius on both corners it shouldn't be an issue but its there.
Ken.
 
Using a knife with (or without) half stops on a regular basis doesn't get me into too much trouble - muscle memory, ya get used to the action, etc. - it's when changing from one to the other that I'm more likely to get bit. :eek:

Thanks Dwight for sharing your knowledge and insight, on this post and many others! :thumbup:
 
KnifeHead said:
Nice explanation, Dwight. I can say from experience that half-stops aren't more safe than cam-end knives :eek: Half-stops will get ya faster and harder than cam-ends. :D And as far as construction goes, half-stops are way harder to execute correctly!

I have a love/hate relationship with half-stops. :p
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I'm all over your explanation about the "get ya"... especially when you are trying to pose a jack knife for pictures, and think you must get the blades at rest between half-stop and closed. :grumpy:
 
waynorth said:
The most sensible explanation I've heard in a long time!!:thumbup:
I knew I loved half-stops, now I know why!!;):D
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Great explanation because I've bitten the tips of my fingers more times with knives with half-stops than without. I'm sure it's just me, though. :D
 
This is a jewel of a thread. My knife education just took another enlightened step forward. I love this place. :)

Thank you! :thumbup:
 
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