Spine whack testing: valid or not?

[SCTorrero]

My anecdotal opinion (which I would quickly change if presented with better data) is that:

1. It tells you something.
2. That "something" is not nearly as significant as one would think.
3. There are better tests for testing the reliability of a lock.
4. The test itself may damage the knife.

 

[scdub]

I am a big fan (boy? ) of the CS Tri-Ad lock in large part because of the series of youtube videos of Andrew Demko comparing their lock mechanism to those of other manufacturers using a “spine-whack machine” and a weight hang. These tests gave insight into certain aspects of strength in a wide variety of “heavy duty” lock designs/manufacturers and were very informative for those who care about the topic, and have helped me decide what knives are more capable of being banged around.

At the same time, I have knives with less-sturdy/zero locks that I also use and value.

Strong locks are only important to me for folding knives that I carry in the role of an “emergency knife”.

In some types of emergencies, tools can get banged around unexpectedly, and I want to prevent that from being a problem to the degree that is possible when a fixed-blade isn’t a viable option for me.

I will therefore do a few LIGHT (~5-10lbs of force) spine whacks the toe of my boot on my “emergency folders” to insure that they aren’t defective.

(By holding the handle between my thumb and forefinger with my other fingers out of the blade path - please, please don’t just put on gloves and start hitting stumps ala JoeX unless you enjoy stitches).

 

[Arathol]

Ah, the key word there is ‘somewhat’. How many people do you know can strike an object with another object at the same exact velocity two or more times? Even dropping a weight on it will be more consistent than a human strike. Maybe I’m splitting hairs here; but if you’re telling me I should base my decisions about buying knives on some attention whore swinging a club at them, I’m gonna ask for a bit more reliable and objective testing methods.

I guess you have no idea what (or who) I am referring to....LCT used a jig with a swing arm and specific weights for each test, ramping up the weight a bit at a time....It was mostly showmanship of course as were all his videos but it did wonders for the reputation of his company, and did show that a knife if made properly doesn't necessarily fail under load.

 

[jbmonkey]

I guess you have no idea what (or who) I am referring to....LCT used a jig with a swing arm and specific weights for each test, ramping up the weight a bit at a time....It was mostly showmanship of course as were all his videos but it did wonders for the reputation of his company, and did show that a knife if made properly doesn't necessarily fail under load.

the Demko tests...is what I call them. always done by Demko and I think Mike Wallace was there on those tests too.......

that was you Mike on those lock tests at cold steel.....? Demko Knives MWallace

 

[Blues]

the Demko tests...is what I call them. always done by Demko and I think Mike Wallace was there on those tests too.......

that was you Mike on those lock tests at cold steel.....? Demko Knives MWallace

I know John Demko was in at least one of those I've seen.

 

[Byrom Hermo]

I’ve lived in 7 decades now and been a knife user for 6 of them. Used non locking knives for at least half that time as well and never had a knife close on me. Also never had the spine ‘whacked’, ever.

 

[Danny Linguini]

I guess you have no idea what (or who) I am referring to....LCT used a jig with a swing arm and specific weights for each test, ramping up the weight a bit at a time....It was mostly showmanship of course as were all his videos but it did wonders for the reputation of his company, and did show that a knife if made properly doesn't necessarily fail under load.

Sorry, nope, I did not know who you were referring to. That sounds a lot more controlled than somebody clubbing it to death, which is most of the supposed ‘testing’ I’ve seen of that nature. Yes, that definitely has a little more credibility.

 

[jbmonkey]

Sorry, nope, I did not know who you were referring to. That sounds a lot more controlled than somebody clubbing it to death, which is most of the supposed ‘testing’ I’ve seen of that nature. Yes, that definitely has a little more credibility.

 

[Andy the Aussie]

One of those dumb internet ideas …

 

[Demko Knives MWallace]

the Demko tests...is what I call them. always done by Demko and I think Mike Wallace was there on those tests too.......

that was you Mike on those lock tests at cold steel.....? Demko Knives MWallace

Yes I was the voice behind the camera giving weights and comments. I wasn’t in the first year of videos but most of them in my 13 yrs with Demko and Cold Steel.

 

[jbmonkey]

Yes I was the voice behind the camera giving weights and comments. I wasn’t in the first year of videos but most of them in my 13 yrs with Demko and Cold Steel.

thought that was ya in alot of those. I miss those tests. always wanted to see who much weight on the tri-ad would finally break it or the blade or handle whatever finally went. I saw one video where y'all had well over 700lbs or close to maybe right below 800lbs..... and held no problem.

that aside I also liked the spine whack/overstrike setup y'all had. good fair and consistent test.

 

[Steely_Gunz]

I voted for it being more complicated.
I often wonder not if a lock with or will not fail a spine whack, but WHY did it fail.
Take the kerfuffle about the ZT knives failing the test a few years ago. I was pretty vocal that I think like 6 out of 8 of mine slipped their locks when given just a few medium wraps against a soft object like a roll of duct tape of a counter covered with a towel. I never had an issue with those knives in real life. I had no idea they would fail the test until I did it. I carried them feeling they were perfectly safe for my intended uses. My question was WHY did a $300 knife billed as being proudly overbuilt with a titanium frame lock and steel insert nested to the tang of the blade fail when a knife costing 10 times less held up to it just fine?

I don't usually test my folders unless it is going to be carried or used as a heavy duty emergency blade. Quite honestly, most of those knives are boring CS Triad lock folders for this very reason. I have tested a few other ones and had no failures, but most of the time I don't think to check it. I did recently check the Ram lock on my brand new Microtech Amphibian simply due to the fact that I had never had one before and there was a thread about it potentially failing. Mine didn't. I also dropped it on the tile floor last night (missed the edge, thankfully) from about 3' up as I tried to swing it open. The lock held just fine.

So while spine whack tests are not statistically significant in any shape of the imagination and NOT carrying a knife because it fails said test but other locks up just fine is rather silly. However, it is curious to know why some fail it and some pass it.

 

[NG VI]

1. It tells you something.
4. The test itself may damage the knife.

Yep, that's why my 'whacks' are always just light taps, I'm only looking to see if I'm holding a knife that will try to take my fingers by surprise

 

[greater]

It's so much more entertaining than a tactitard "tough" "tactical" "hard use" liner/frame lock marketing ad with pictures of soldiers, slogans, and flags in the background from our usual suspects.

Yes more spine "tap" ??? what ? no no progressive from light to bashing hard lets see how those marketing claims hold up. I am very glad these videos are posted all over the web.

 

[corey4]

a few weeks ago i read a post somewhere that the person claimed that the lock failed and almost took his fingers off while cutting banding off skids at work. he had the spine on the hard surface under the banding, blade facing up and using the tip area as the fulcrum and lifting to cut the band. would a couple of spine hits to test lock up shown the lock was insufficient? i dunno. i don’t whack or baton with my knives. i want a cutting tool, not a splitting wedge.

i have often wondered what do people do when they need a cutting edge for doing knife things after they just got done splitting wood with the knife.

i do not recall the forum or knife brand or lock style.

 

[MSchott]

Agreed

I actually did this recently with 2 of my Hinderers, against the palm of my hand (not crazy hard, but still not smart I know), and they were fine.
I really do question the validity of that recent youtube video that shows them failing.
The same guy who posted that has also previously mentioned he modifies the lockbar tension on his knives to his liking.

So no, I don’t consider it anything but
antagonistic clickbait if it’s not done scientifically. Cold Steel’s older videos were interesting.

I didn’t watch that guy’s video but I did test my X-18 3.5 by hitting the spine pretty hard against a block of wood. Nothing happened.

 

[Danke42]

I voted for it being more complicated.
I often wonder not if a lock with or will not fail a spine whack, but WHY did it fail.
Take the kerfuffle about the ZT knives failing the test a few years ago. I was pretty vocal that I think like 6 out of 8 of mine slipped their locks when given just a few medium wraps against a soft object like a roll of duct tape of a counter covered with a towel. I never had an issue with those knives in real life. I had no idea they would fail the test until I did it. I carried them feeling they were perfectly safe for my intended uses. My question was WHY did a $300 knife billed as being proudly overbuilt with a titanium frame lock and steel insert nested to the tang of the blade fail when a knife costing 10 times less held up to it just fine?

I don't usually test my folders unless it is going to be carried or used as a heavy duty emergency blade. Quite honestly, most of those knives are boring CS Triad lock folders for this very reason. I have tested a few other ones and had no failures, but most of the time I don't think to check it. I did recently check the Ram lock on my brand new Microtech Amphibian simply due to the fact that I had never had one before and there was a thread about it potentially failing. Mine didn't. I also dropped it on the tile floor last night (missed the edge, thankfully) from about 3' up as I tried to swing it open. The lock held just fine.

So while spine whack tests are not statistically significant in any shape of the imagination and NOT carrying a knife because it fails said test but other locks up just fine is rather silly. However, it is curious to know why some fail it and some pass it.

I would think the ZT problem is from the lock and the blade syncing up frequency and "walking" each other apart. It won't do it on the first try but it will do it after a few hits.

 

[Another Shepherd]

Some people seem unable to grasp the fact that accidents happen in real life. I have had the spine of a folder I was using unintentionally whacked by the very hard skull of a 100-lb lamb traveling at high speed. The knife was knocked out of my hand and landed about 6 feet away. I am happy that the compression lock on the Caribbean Salt held.

 

[Arathol]

Yes I was the voice behind the camera giving weights and comments. I wasn’t in the first year of videos but most of them in my 13 yrs with Demko and Cold Steel.

Might want to set the record straight in this thread also.....

https://www.bladeforums.com/threads/blade-lock.1977690/page-4#post-22545760

 

[stabman]

While I fully support the right of others folks to do whatever the heck they want with their own knives, the belief that spine whacking is a test that consumers should do themselves is the biggest reason I don't want to buy used folders. Especially since some people feel it is a "test" they should do on a periodic basis.

Not even so keen on buying used fixed blades with what some people think is reasonable use...