strength of the axis lock?

[ftkinney]

a while ago sal had the great thread on lock types and the axis lock was consided "very strong" i was wondering what this ment numericaly i.e.: foot pounds, etc and how this to the compared to the compression locks and strong lockbacks?



FTK

[sal]

On the knife we tested, it was up there in the high numbers with the Rolling lock, compression lock and the Chinook lockback.
(MBC area 200 inch lbs / inch of blade length)

sal

[Sword and Shield]

About the lock strength, how does that equate to other companies' claims of strength? For example, Cold Steel claims a lock will hold 120 pounds 4.5" from the pivot, or as far as possible. Is that the same test a Spyderco which holds 200+ completes? Or is there some other way of looking at this I haven't seen?

Thanks. <img src="smile.gif" width=15 height=15 align=middle>

Keepin' it real...real sharp, that is.

[Carlos]

Spyderco has a machine that breaks locks in a very controlled and measured way.

MBC lock rating is 200# per inch of blade length. A 4.5&quot; MBC Spyderco should thus be able to take up to 900# of presure before the lock gives.

The Cold Steel you mention takes 120# of total pressure, or 26.6# per inch of blade length. I don't think this would meet Spyderco's criteria even for &quot;medium duty.&quot;

Edited by - Carlos on 12/16/2001 7:11:47 AM

[sal]

We built our breaking machine to be able to test batches and determine if our locks were meeting our own standards.

Though we often break other companies locks, we do not feel that it is our place to make comments on their strength. If they are very strong, I don't mind giving credit for that achievement, but if they're not as claimed by those mfrs, then we prefer to keep our information to ourselves.

sal

[Tightwad]

Sal, Thank's for the information. As far as real world lock strength
goes any well made &quot;Locking Back&quot; type of knife should be more
than enough for the &quot;average&quot; user.

That to me is ANY lock that engages the top back of the blade.
Liner locks are a different animal. I think where the average Joe
gets in trouble is expecting a folding knife to be as strong as a
striaght blade that is ONE piece of metal. With that in mind I'd
say that all of the name makers are careful enough to produce a
quality locking back knife that will serve all but the most severe
duty ( you need a straight blade work) safely.

[Sword and Shield]

Thanks Sal. I always wondered about claims as to strength, as some companies seem to inflate their claims a bit. I'm glad I asked before I blindly believed a claim which seemed too good to be true! <img src="smile.gif" width=15 height=15 align=middle>

Keepin' it real...real sharp, that is.

[ftkinney]

sal thanks for the information.

FTK

[Pachucko]

So where could one find this listing/classification? Ie. MBC Spyderco, Medium Duty Spyderco, etc... I'm guessing examples of MBC's would be the Chinook, the Massad Ayoob, and the basic FRN models would be Medium Duty? Thanks---Pachucks

[Carlos]

There is no such listing as yet. I think that Spyderco considered stating that kind of information in their marketing/packaging of each knife, but I guess the ideas been dropped. The way marketing works in the US, I gues it would create more headaches for Spyderco than anything. Notice how every company wants to claim that their xxx lock is the strongest?

The Ayoob I believe is Heavy Duty rather than MBC, and some of the basic FRNs like the Endura are also Heavy Duty.

[ftkinney]

Carlos i think you are right if spyderco said a knife at X amount of # per inch another nife company might calculate the number a diffent way and if 400# of strengh is printed real big in red on an ad or on the box. that is what people will think. not reading the fine print staiting that the 400# is measured half an inch from the pivot point or what what ever gives them a good figure. thanks for every ones imput.

is there a machine that opens and closes the blade to test for repeat locking and unlocking?

FTK

Edited by - ftkinney on 12/18/2001 11:12:57 AM

[ghostguy1]

I know this an old series of posts but I had to add my two cents worth while reading it because there seems to be errors in the calculations. First, the measures discussed here about lock strength seem to be measures of torque. A lock can support much more weight when the weight is applied right next to the lock than 4 inches from the lock. There is more torque applied in the latter scenario. 10 lbs applied one inch from the lock is equivalent to 10 inch lbs. 10 lbs applied 4 inches from the lock is 10 X 4 = 40 inch lbs. Now, I own many spyderco/cold steel/bench made/ zt/ buck/sog knives. I like the workmanship and locks if they are built well. But I wanted to correct what seems to be miss calculations in this thread. Sal states that a MBC blade must be in the area of 200 in lbs per inch of blade length. Say the Chinook 1 is tested at about 3.5 inches. That means the "strength rating" is 3.5 inches X 200 in-lbs/inch of blade length =700 inch lbs. If you compare apples to apples you have to be consistent in your units. Most knife makers that I've seen on compare lock stength in inch lbs. When cold steel says that a knive can support 120 lbs 4 inches from the lock, using sal's measure and units, that is the same as saying the lock is rated at 120 inch lbs per inch of blade from the lock. The measure of strength is then 480 in lbs and not the 26.6 lbs per inch described in a previous post. If the blade can support 235 lbs at 4 inches from the lock it strength is 4 X 235 = 940 inch lbs. That is the way it is calculated by alan eliswitz (sp?) when testing the hogue knife he designed and that is the same way it is calculated by Andrew Demko. Like I said before, I own a wide variety of knives, but let's be fair in terms of how we describe and calculate the numbers. Many knife makers make strong and beautiful knives.

[Blerv]

It's awesome that Sal would give kudos to BM for the Axis Lock.

What I mean is that even classifying it in their realm for "MBC" says that the product matches the description. Sal and Co could have simply not responded keeping the mystery in our heads. I had no idea it was this strong and am impressed more with BM than before.

Sometimes there is more to being a good company than simply not saying bad things. Saying good things and tipping your hat at your competitors is a hard task. :)

[mikerestivo]

This may have set the "giving rise to Zombies" post record.

[Tsujigiri]

What exactly does MBC stand for?

Also, where do the Manix 2 and Gayle Bradley fit in? I ask because they seem to be mentioned the most as Spyderco's heavy duty knives.

[Brad S.]

Wow. Oldest tread ever.

[defenestrate]

MBC = Martial Blade Craft

Not certain about the Bradley (though I'm pretty sure it's one of the stouter linerlocks) but the Manix 2 uses the CBBL which is known to be rather stout. I believe they qualify as MBC rated generally.

[VashHash]

What is the rolling lock

[dialex]

I know this an old series of posts but I had to add my two cents worth while reading it because there seems to be errors in the calculations. First, the measures discussed here about lock strength seem to be measures of torque. A lock can support much more weight when the weight is applied right next to the lock than 4 inches from the lock. There is more torque applied in the latter scenario. 10 lbs applied one inch from the lock is equivalent to 10 inch lbs. 10 lbs applied 4 inches from the lock is 10 X 4 = 40 inch lbs. Now, I own many spyderco/cold steel/bench made/ zt/ buck/sog knives. I like the workmanship and locks if they are built well. But I wanted to correct what seems to be miss calculations in this thread. Sal states that a MBC blade must be in the area of 200 in lbs per inch of blade length. Say the Chinook 1 is tested at about 3.5 inches. That means the "strength rating" is 3.5 inches X 200 in-lbs/inch of blade length =700 inch lbs. If you compare apples to apples you have to be consistent in your units. Most knife makers that I've seen on compare lock stength in inch lbs. When cold steel says that a knive can support 120 lbs 4 inches from the lock, using sal's measure and units, that is the same as saying the lock is rated at 120 inch lbs per inch of blade from the lock. The measure of strength is then 480 in lbs and not the 26.6 lbs per inch described in a previous post. If the blade can support 235 lbs at 4 inches from the lock it strength is 4 X 235 = 940 inch lbs. That is the way it is calculated by alan eliswitz (sp?) when testing the hogue knife he designed and that is the same way it is calculated by Andrew Demko. Like I said before, I own a wide variety of knives, but let's be fair in terms of how we describe and calculate the numbers. Many knife makers make strong and beautiful knives.

Indeed, this is something that bothers me as well. I mean, according to the statements above, if you have say a 4" blade knife, it will hold 4 x 200 lbs near the tip but only 1 x 200 lbs near the pivot? :confused:

[dialex]

What is the rolling lock

It's a locking mechanism designed by Mel Pardue (IIRC) and I think it was used for the first time at the REKAT Sifu. A variant of this particular lock is currently used by Benchmade for their Mini Ambush.

[jzmtl]

Indeed, this is something that bothers me as well. I mean, according to the statements above, if you have say a 4" blade knife, it will hold 4 x 200 lbs near the tip but only 1 x 200 lbs near the pivot? :confused:

I always thought it simply means this, the inch.lb is the base torque value, and length of blade is the multiplication factor. In case of a 3.5" MBC lock, it means the lock itself would have to stand up to 200 in.lb X 3.5" = 700 in.lb of torque. It makes sense because this way no matter how long the blade in the knife is, locks in the same rating category would be able to stand up to the same amount of pressure applied to tip of blade.

So essentially rating is not purely based on lock strength, but rather whole knife. The longer the blade, the stronger lock needs to be in order to get the same rating.

[The Mentaculous]

Yes, I would think 200 in lbs per inch on a 4" knife means it can withstand 200 in lbs at 4 inches, and 800 in lbs at 1 inch. If the knife was 2" blade instead of 4", it would only have to be 1/2 as strong overall to still qualify--200 in lbs at 2", as opposed to the 400 inch lbs at 2" on a 4" knife. This makes complete sense, just like jzmtl said, because the longer a blade is, the more leverage there is being applied.

[The Deacon]

Indeed, this is something that bothers me as well. I mean, according to the statements above, if you have say a 4" blade knife, it will hold 4 x 200 lbs near the tip but only 1 x 200 lbs near the pivot? :confused:No Alex, it's the other way around.

What Sal's actually saying is that the lock of a 4" bladed knife needs to be four times as strong as that of a 1" bladed knife, and twice as strong as that of a two inch bladed knife, to achieve the same "inch pounds per inch" rating. So a 2" bladed knife could be MBC rated with a (relatively) weaker lock than a 4" bladed one. That makes perfect sense, since the blade of the 2" knife can never exert as much leverage on the pivot and lock as a 4" blade can. So an MBC rated 4" blade would need an 800 in/lb lock (200 lb X 4") while a 2" bladed one would only need a 400 in/lb lock (200 lb X 2").

[Tsujigiri]

MBC = Martial Blade Craft

Not certain about the Bradley (though I'm pretty sure it's one of the stouter linerlocks) but the Manix 2 uses the CBBL which is known to be rather stout. I believe they qualify as MBC rated generally.

Great, thanks!

[ghostguy1]

My friend, I don't think that's what it means. Obviously, Sal can better explain what is meant, but I think, based on his definition or specifications, for a martial blade craft knife to be classified as such, it must be able to support or withstand 200 in lbs of force/in of knife blade. Since the greatest torque can be applied end of the blade the calculation would be made with the full length of the blade. So to qualify as a MBC knife a one inch blade should be able to support 200 in lbs torque, a 2 inch knife should be able to support 400 in lbs of torque, a 3 inch knife should be able to support 600 in lbs of torque and so on. In light that when alan elishewitz tested a number of factory knives and one custom knife and found that the average torque supported was only 300 something in lbs. It means that most of the spyderco knives would exceed the strength of the other knives. However, for those who are not impressed by the demonstration of a knife handling 400 lbs 4 inches from the pivot, I don't know what to tell you because I am impressed. It means that knife can handle 1600 in lbs of torque which is more than twice that of the chinook if the numbers above If the numbers are correct above than that knife can support or handle more than twice the torque of the chinook. If I remember my college physics, torque is equal to force X torque arm length. Wt is not truly equal to force because force is equal to mass X acceleration, but it is good enough for this argument since acceleration is acceleration of gravity which is constant in this instance. If the numbers are correct above, the chinook should be able to handle 200 in lbs per inch of blade X 3.5 inches which is equal to 700 in lbs. It also means that the knife should be able to handle 700 lbs one inch from the pivot. I don't know if this makes sense. Hope it does. :)