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Folder Strength
- Thread starter Bumppo
- Start date
Are you talking about the pivot? if so most blades will break before you apply enough torque to break the pivot.
- Joined
- Oct 30, 2005
- Messages
- 5,171
Pins are weak, so a bolted pivot is stronger for twisting.
I'd personally like to see more of the larger headed and diameter pivot bolts as seen on many customs and some few production knives, since I've dealt with pull-throughs of the scale materials and some wear that could have been avoided by spreading out the load over a greater surface area.
I'd personally like to see more of the larger headed and diameter pivot bolts as seen on many customs and some few production knives, since I've dealt with pull-throughs of the scale materials and some wear that could have been avoided by spreading out the load over a greater surface area.
- Joined
- Aug 27, 2004
- Messages
- 12,957
I can see where a larger type screw could be seen as stronger by the solid diameter difference but honestly I've twisted off more larger size heads on 4-40 and 6-32 screws than I ever have on smaller ones although that has happened also. If any area stands out as being more durable here I'd say its the type of driver needed to remove and tighten the screw. Torx seems far better than hex head to me for durability, particularly in the smaller 1-70 and 2-56 sizes. It seems to me the flat head type screws are stronger than button head or socket head screws across the board after using all types in my folders. Thats just my own feelings on it though.
As for the pivot barrels. Well, I find that rather interesting too because the general consensus, at least among end line users seems to be that a bigger diameter pivot does something to make it stronger when it seems to me that the actual thickness of the sidewalls on many of the so called 'bull pivot' barrels is actually thinner than a smaller 1/8" barrel which is quite thick looking by comparison so I don't know how much merit I give to that argument. I think people just see bigger and think stronger is all thats really happening. I recall once clamping a rather bulky pivot in my vice grip to hold it to shorten it just a bit only to see that the small pliers actually sqeezed it in some and I've never done that to one of the 1/8" stainless pivot barrels I use often in my folders if that is any indication.
It takes a great deal of force to shear even a number 2 size screw let alone something bigger in diameter than this. Many times the lip of the barrels is shallow where it connects from the lock side to the non lock side in a frame or liner lock or from one liner to the other in conventional knives or the length of the barrel is cut short so its only in one side well while barely in the other side for nothing much at all but the screw holding it there or some other weak point will go long before the pins or barrels would even be at a stress point to worry with. All these things can play into how well the system holds up under load. And that is what its all about when you assemble a folder together. Its not so much the individual components, although those do of course contribute but its the way the entire system comes together that adds up to whether or not its a solid strong design. As its been pointed out already regarding the blade would break far easier than this occurring in most folders I'll leave it at that.
STR
As for the pivot barrels. Well, I find that rather interesting too because the general consensus, at least among end line users seems to be that a bigger diameter pivot does something to make it stronger when it seems to me that the actual thickness of the sidewalls on many of the so called 'bull pivot' barrels is actually thinner than a smaller 1/8" barrel which is quite thick looking by comparison so I don't know how much merit I give to that argument. I think people just see bigger and think stronger is all thats really happening. I recall once clamping a rather bulky pivot in my vice grip to hold it to shorten it just a bit only to see that the small pliers actually sqeezed it in some and I've never done that to one of the 1/8" stainless pivot barrels I use often in my folders if that is any indication.
It takes a great deal of force to shear even a number 2 size screw let alone something bigger in diameter than this. Many times the lip of the barrels is shallow where it connects from the lock side to the non lock side in a frame or liner lock or from one liner to the other in conventional knives or the length of the barrel is cut short so its only in one side well while barely in the other side for nothing much at all but the screw holding it there or some other weak point will go long before the pins or barrels would even be at a stress point to worry with. All these things can play into how well the system holds up under load. And that is what its all about when you assemble a folder together. Its not so much the individual components, although those do of course contribute but its the way the entire system comes together that adds up to whether or not its a solid strong design. As its been pointed out already regarding the blade would break far easier than this occurring in most folders I'll leave it at that.
STR
And there you have it.
One thought to add - older knives with "tiny" pivots may have loosened, but failure was rare. It's only in today's market that huge pivots sell - because users plan on doing the wrong thing with their knives.
Back in the day, if you needed to pry, you made the tool with the knife, which was a hard earned tool and treated with respect. Today, you insert and twist, thinking you can always get another, and besides, fixed blades are so much harder to carry.
A lot of it is based on a completely different concept of tool use.
Like the lady who actually thought her Hummer could jump over a fountain on a Florida campus, there are a lot of users with completely unrealistic views about how to use a knife.
One thought to add - older knives with "tiny" pivots may have loosened, but failure was rare. It's only in today's market that huge pivots sell - because users plan on doing the wrong thing with their knives.
Back in the day, if you needed to pry, you made the tool with the knife, which was a hard earned tool and treated with respect. Today, you insert and twist, thinking you can always get another, and besides, fixed blades are so much harder to carry.
A lot of it is based on a completely different concept of tool use.
Like the lady who actually thought her Hummer could jump over a fountain on a Florida campus, there are a lot of users with completely unrealistic views about how to use a knife.
Like the lady who actually thought her Hummer could jump over a fountain on a Florida campus, there are a lot of users with completely unrealistic views about how to use a knife.
How in the World did I miss this on the news?!! Link? That had to be pretty funny to watch, so I'd like to check it out.
Have to agree, use the right tool for the job. Putting lateral force on a joint is always going to 'work it' a bit more each time until it is loose, or flat out fails. Look for a heavy duty built Strider type folder if you need this type strength.
How in the World did I miss this on the news?!! Link? That had to be pretty funny to watch, so I'd like to check it out.
Have to agree, use the right tool for the job. Putting lateral force on a joint is always going to 'work it' a bit more each time until it is loose, or flat out fails. Look for a heavy duty built Strider type folder if you need this type strength.