The Grand Unified Traditional Pull Scale

This actually changed my "pull" perspective.

I don't have any knives that are impossible to open by hand, and I don't have any that don't stay closed, so I had not really put them in my equation.

I handed my #73 pioneer to a friend to look at. He folded his nail back, and told me he could not open it. He is a Sheriff (search and rescue), and former swat member. I put that knife no higher than a 6 on my pull scale. I can open it with my thumb, but also with every other nail on my hand, including my pinky nail. It was a 7/8 when brand new, before cleaning and oiling.
 
In a thread back in June http://www.bladeforums.com/forums/showthread.php/968331-On-a-scale-of-0-10-what-do-you-prefer I briefly discussed the jig I've been using to measure pull scales. The knife being tested is clamped at the end away from the pivot of the blade being measured, with the springs up/blade backs down (so the blade opens down). The sides rest on a sort of shelf fitted to the knife but not touching the blades. (I think the best way to hold it would really be to use something like bondo, but that would probably sacrifice the knife covers.)

To measure the pull, I originally tried a fish scale but it wasn't consistent. I then went to a recording trigger-pull scale which unfortunately didn't have a large enough range. I've finally settled on suspending weights on a rod, and recording at what weight the knife opened 1/3-1/2 of the way. A scale designed to measure pull on archery tackle might work better, but I don't have access to such a scale.

I clamp the blade at the nail nick in aluminum-padded jaws of a pair of vise grips, with the weights suspended from the vise grips. (Did I mention how much I admired Rube Goldberg as kid?;)) I usually do 5 trials and average the results, but I'm working just for my own amusement. I've always thought manufacturers must have a better way of measuring pull, but perhaps they rely on something like the gauge like Phil described, one that measures force the spring exerts on the tang.

The Vic Soldiers I've measured (all 2 of 'em) were in the "4-5" range on that scale, but that brings up the question of if we even need to bother measuring the pull of knives that aren't usable? I know of one knife that measured about 40.5# that over 50 people (farmers and mechanics, mostly) have been unable to open. If (using the numbers I had in June) we throw out the knives that people haven't been able to open by hand, those Vic Soldiers would fall into the upper "5-6" range.
 
brets-ftw said:
I agree with Rich, it's a little hard to match other people's personal scales.
Click to expand...

It's probably a good scale, but I KNOW that I have trouble trying to open blades that other folks find pretty easy. So I just take this into consideration when I shop.
 
Just thinking out loud here.
I have NEVER encountered a knife that I could not get open with my bare fingernail.
Mark
 
Ramrodmb said:
Just thinking out loud here.
I have NEVER encountered a knife that I could not get open with my bare fingernail.
Mark
Click to expand...

Good bump for a helpful thread.

I will add that I believe opening traditional knives does strength your nails over time. I used to fold my thumb nail once a month or so with knives such as the GEC 73 but haven't folded a nail in over a year now that I always carry a traditional.
 
So what is it ever decided what the rating for the main blade on a Vic Pioneer would be? I always assumed that it was about a 6 or 7.
 
Using the Goldbergian-device I mentioned above, I've now checked pull on >3,500 modern knives. Based on about 20 samples, the Vic Pioneer falls around "4+" on a 1-10 scale.
 
Based on the scale in the OP I should say most knives fall into the fairly wide 6-7 range. Don't see many too stiff to carry (8) or too soft to carry(5) really.
 
I think that every new Camillus TL-29 I've handled (six or seven in all) falls squarely into the 8 range. I can use a new TL-29, but prefer the file it down into 7 range.

I can definitely live with a Pioneer rating at 6. I consider the Pioneer to be pretty much the gold standard in terms of pull.

Also, after handling countless used Camillus 99 scouts, the main blade usually rates at a 5. I think that Camillus often tried to get their slipjoints to a 5 as a standard.
 
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