Review of the Zero Tolerance ZT 0850

Going to SHOT Show can have its good and bad points.  Yes, there’s so much of interest to see.  ThruMyLens fans will recall I went to SHOT earlier this year (my first time).  While I was there, I did stop by the Zero Tolerance booth to check out their latest knife offerings for 2017.  The ZT booth was positively swamped the first time I swung by.  Later in the week, after being pretty exhausted from the marathon that is SHOT, I stopped by again.  I took a look at the collection and recall coming away thinking “well good…I’m going to save money on knives this year.”  I didn’t really like anything I saw.  I think it was the fatigue of SHOT which colored that initial perception.  Then I started reading and seeing more about the new ZT 0850.  The more I saw, the more I liked.  Several years ago I got my hands on the rare and coveted ZT 0777M390 (known by many as the “triple 7”).  I eventually sold it (for reasons I explain below) but it did have some pretty revolutionary features not since seen from ZT.  In particular, the titanium sub-frame lock on the 0777 was a fascinating innovation.  Since selling the 0777, I have missed some of those great features which the 0777 had.  Long story short – I ordered a ZT 0850 once they starting hitting the market in the Spring of 2017.

The ZT 0850 has an interesting development story.  It’s design represents a collaboration between two of the knife world’s hottest makers – Todd Rexford and Dmitry Sinkevich.  Apparently the two knife industry rock stars made a very limited run based their collaborative design (which sold for astronomical amounts) before working with Zero Tolerance on the design to create the ZT 0850.  

The Titanium Sub-Frame Lock

We first saw the KAI/Zero Tolerance patented sub-frame lock on the previously mentioned ZT 0777M390.  In my humble opinion, the importance of the sub-frame lock design cannot be understated.   From a pocket knife perspective, the biggest detriment to the otherwise fantastic Chris Reeve titanium frame lock design is the corresponding weight inherent to having a knife with a titanium scale (and frame lock) in your pocket.  KAI (parent company of Zero Tolerance) came up with a way to embed a titanium frame lock within a knife scale made from much lighter material.  Like the award-winning ZT 0777, the scales of the ZT 0850 are constructed entirely from carbon fiber.  The titanium sub-frame lock is set into the lock side carbon fiber scale, providing the lock strength and stability of titanium AND the weight savings of both scales being hewn from carbon fiber.  Despite the fact that the ZT 0850 has a relatively large blade of 3.75″ and a handle length of 5″, the total weight comes in at just 4.3oz.  The sub-frame lock also features the ZT steel insert into the lock bar which creates a steel-on-steel lock interface, eliminating another potential negative consequence of the titanium frame lock design – “lock stick.”  Lock stick was not uncommon to the early implementations of the titanium frame lock, where the titanium lock face engaged directly with steel.  The ZT steel insert (another innovation first seen in the ZT 0777) all but eliminates lock stick.

The ZT 0850 also features an upgraded pocket clip than what is typically seen on most ZT production models.  It’s “3D” milled titanium (as opposed to the standard stamped metal ZT pocket clip) with a bead blasted finish and again very reminiscent of the ZT 0777.  It’s a little less elaborate, and the design isn’t quite as “deep carry” as the ZT 0777 pocket clip, but it’s a nice upgraded feature.

The Sinkevich/Rexford ZT0850 design is has a firearm theme – you can see it in the pivot, thumb studs, and back spacer which all have the appearance of a six-shot revolver cylinder.  The thumb stud and back spacer (which looks like a bullet at one end) are milled from aluminum for added weight savings.  Some have been critical of the use of aluminum in the ZT 0850 because it’s seen as a “cheap” material that not robust enough for a hard-use knife.  I strongly disagree – aluminum is actually quite difficult to machine, and is actually more expensive to use.  The strength to weight ratio of aluminum is quite positive so I see it as a good choice.  The other aesthetic uniqueness which the ZT 0850 has is the blue woven into the carbon fiber scales.  In short, I love it – it looks fantastic.  As much as I have grown to like carbon fiber scales on a knife, it’s getting to be a bit overdone in the industry.  Black carbon fiber scales are getting boring.

Much like black carbon fiber is overdone, flipper deployment knives are as well, so the thumb-stud deployment of the ZT 0850 is a breath of fresh air.  Don’t get me wrong – I love flippers, and ZT does them better than just about anyone.  But variety is the spice of life, and a knife with well-designed thumb studs, combined with phosphorus bronze washers is every bit as smooth and fun to deploy as a flipper.  The ZT 0850 is amazingly smooth and the blade rockets out with authority every time.

The Blade

The modified sheeps foot blade (another tip o’ the hat to the 0777?) is perhaps the most controversial design element of the ZT 0850.  Admittedly, I was initially a bit turned off by it.  But it definitely grew on me after seeing it at SHOT Show – the more I saw it, the more I liked it.  Functionally, it’s fantastic.  The base of the spine has some nicely done jimping going into the thumb studs which definitely improves the purchase and control of the knife under hard use.  But the swooping section immediately after the thumb studs creates a great secondary position for the thumb, allowing the user to “choke up” for more fine control.

CPM 20CV was the steel chosen for the blade of the ZT 0850.  If you’ve read any of my other knife reviews, you’re well aware that Bohler M390 steel is my favorite choice for knife blade steel.  It’s so good that various steel vendors have come up with two other alternative steel formulas which are, chemically speaking, nearly identical to Bohler M390 (click here to see a chart that compares them).  In short, CPM 20CV should perform every bit as well as M390 blade steel for my uses so I’m quite pleased with the choice.

The coveted “triple 7” ZT 0777  won Bladeshow’s 2011 Knife of the Year for its fantastic design and features.  I would argue that the ZT 0850 is better.  Why?  Because it’s a regular production model.  The 0777 variants aren’t available any longer and good luck finding any replacement parts for it – ultimately why I decided to sell it the one I owned.  ZT has gone to MAP pricing so you won’t find the ZT 0850 below $320.00.  So you might as well purchase it from Amazon and get their free shipping and extra points awards for using an Amazon credit card.

In addition to this written photo review, I’ve recorded a video supplement on the ZT 0850:

Addendum:  A reader of this review commented (see below) that this knife uses the KAI/ZT KVT ball bearing system and not phosphorus bronze washers.  So I disassembled the knife to prove that I was correct…and I added some grease to the pivot for good measure while I was at it: