SOG Arc lock initial impressions


knife law moderator
Dec 25, 1998
I received a SOG Night Vision today from Cumberland Knives. I was really curious about the Arc Lock mechanism. From the pictures I have seen it looks very similar to the Axis lock. Readily apparent is the fact that track that the locking bar rides in is curved where the axis is straight. The bar also has tension on it via what appears to be two omega type springs. Here is the major difference: Visualize an upside down T, the bottom part of the upside down T is the locking bar. The other part of the upside down T (perpendicular to the locking bar) is attached to the knife directly behind the stop pin.


The locking bar pivots back and forth on this. I really can't decide if this is an improvement over the Axis lock idea or a detriment.

The feel of the knife while opening is very similar to the Axis lock. Lockup is secure, with no blade play in any direction. I could not get the knife to close with spine whacks or torquing. The grip is fairly comfortable. The blade came shaving sharp out of the box.

Three screws secure the clip. One large (like REKAT's) and two smaller ones. The clip screws into the steel liners. The clip is reversible and tip up. The clip leaves quite a bit of the handle sticking out of the pocket (about 1"). I like my knives to ride a little lower, but some prefer their knives to ride higher. The clip is very secure.

I am not crazy about tanto's or partially serrated blades, but I think this blade design looks really good. I am not sure as of yet how it will perform, but I think it will be
more than adequate. The main part of the blade is hollow ground and the secondary tanto edge is flat ground.

Overall fit and finish of the Night Vision is superb. On first impression, I really like it. I am looking forward to putting it through its paces.This is my first SOG knife (I have a powerlock multitool). If the Night Vision is any indication SOG is underrated (on the forums anyway). They also have a titanium handled version and a zytel version on the way. I would like to see someone like Joe Talmadge handle one and see what he thinks about the Arc Lock and how it relates to the Axis. I would also like to see SOG make a plain edge version.

Dennis Bible
I too would like to see more of a comparason between the Axis and the Arc lock. I wish SOG would make some plain edged blades for their new line of folders. I just hate partially serrated. And I think companies should work more on their clip design.
Al Mar SERE 2000 clip design is the best I seen so far. The knife rides low in the pocket so you dont have to worry of it catching on something and falling out. I also like more discrete carry. Now if SOG does that then I would buy it.


Dennis, thanks for sharing your impressions.
You are lucky chap!
My Night Vision has "stuck" at Warsaw airport, Friday I received notification. For the another time I should prove our customs to do not lay duty on my parcel. Hope I will been lucky and Monday or Tuesday this baby will be at home

However this time I'm drooling of impatience, they really destroyed my weekend mood

When I'll receive mine and play with it some time I'll share my impressions, of course. Also, I will try to bag from SOG some scheme how it works to hang it here.

Dennis - Thanks for your initial impressions. Once you have a chance to play with and test it more, please update everyone with your findings.

Sergiusz - How frustrating for you! I've had my order in for these since February...its been torture waiting! I can promise WILL be worth the wait! We'll be eagerly looking forward to your review (they're always fair and informative). Maybe you can also give us a quick "initial impression" once you get it.


I am not one to hide my feelings, and I really like this knife. I was thinking about the upside down T design and realized that for the lock to break it would have to break through the steel liners in TWO places. One at the lock bar and the other where the pivot is screwed into the liner! I would love to see some test results on this design. Along with a cut away picture.

Dennis Bible
What I want to know is, how much tang metal support is there around the pivot, given that the large "cutout" behind the cutting edge necessary to allow the knife to close seems to run WAY too close to the pivot pin?

Until I get assurances that it isn't a problem, or better yet pics of the blade removed from the rest of the knife, I can't order the PE2 sight-unseen the moment it ships.

Why am I the only one noticing that the pivot pin positioning is seriously assymetrical and real close to a cutaway?

Hi Jim,

I have the ArcLock knives here in my hand as we "speak" (Night Vision, Vision, and Pentagon Elite). I understand your concern relative to less tang in the pivot area due to the ArcLock mechanism.

Let me say that there is substantial steel to make the system solid. Also, between excellent steels being used (strong) and a thick blade, strength concerns should not be an issue.

Maybe I am not thinking this all the way through, but the only scenario I can think of in which breakage in that location would happen would be prying...a task in which NO folding knife is designed to perform.

Last resort...warranty. SOG maintains a liberal warranty policy. If it broke and was not abused or misused, it is simply covered under warranty. Period.

Personally, I'm not concerned with the marginal loss of steel in the pivot area. It is a solid performer and performed extraordinarily well in our stress tests!

Hope this helps.


There actually is more steel there than it looks like. The cutout is a grove that the lock fits in to help keep the knife closed. Still I wouldn't mind seeing more steel there.

Dennis Bible
I like the looks of the knife, but the design will need to prove itself over time.
It appears as though there is very, very little material where I would want excess material.

Though I have only one tanto, I find they are more useful for everyday chores than many give them credit for.

What are the specs and price on the knife?
Our turtle express (polish courier shipping service) delivered me the Night Vision literally two hours ago.

Very solidly built knife. No doubts about seeming lack of steel at blade tang near the pivot. What we can see on pictures behind the edge is only notch, which keeps blade in closed position. Real blade tang is covered and has quite enough steel around the pivot.

Arc Lock on the pictures looks quite similarly to Benchmade Axis Lock but it works completely differently. In my opinion not horizontal bar (or at least not only) takes the negative load. First and foremost is loaded this vertical part of upside down "T" following Dennis description, and it is loaded directly along it's length. Taking into consideration that this arm is about 3,5 mm thick, at least 4 mm wide and only about 10 mm long it is hard to imagine situation when it could lose stability. I rather could imagine that very high load could bend this arm's pivot which is visible above lock release button. Think this pivot is not too thick, it goes into 4-mm thick arm so it could have no more than 2-2,5 mm in diameter. But it is quite difficult to bend 2-mm thick pivot especially if it has 3,5-mm length only. And even it would start to bend the axis joining lock release buttons would be loaded immediately and entire mechanism would start to work like BM Axis Lock.
I must play with it somewhat more to refine my first impression and to learn better how it works...

I'm afraid my description is somewhat vague, later I'll try to make a drawing to illustrate it or I'll take knife apart and make some photos.
Ron, will you void my warranty if I'll do it?
Or maybe you have some schemes to hang them here?

As to blade shape, in my honest opinion it has nothing to do with traditional Japanese tanto knives. But this blade has not too much in common even with tantos rebuilt from broken medieval Japanese sword or with Bob Lum's Americanized tanto. I could consider it as quite independent blade design, which so far has not his own name.

Friends, I have crazy idea - let's try to name it!
My propositions would be pyramid point or piercing point.

Ron, what do you think about? Maybe SOG could announce contest and found prize to honor the best idea? Contests are very fashionable now

[This message has been edited by Sergiusz Mitin (edited 07-18-2000).]
Sergiusz, I am really looking forward to your review. What other initial impressions do you have? Do you like it alot? What are your thoughts on the blade design?

Dennis Bible
Dennis, thanks for kind words

I would like to "brandish" with this knife some weeks to refine and to clear my impressions. Of course then I'll share them.
Since that angular point isn't a traditional Japanese knife shape, I've been calling it a Geo-Tanto or a Ninja Steak Knife. When you use it at the little secondary point is the only part of the blade that touches the china plate, so the rest of the edge stays sharp.

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