ZT 0561


Knives :

This review consists of :

Introduction and Specifications

Maker Webpage : ZT 0561 :

DESIGNED BY RICK HINDERER, REALIZED BY ZERO TOLERANCE

Based on Rick's crave-worthy XM-18, the new Zero Tolerance 0561 is one completely amazing knife.

First, the blade. It's pure ELMAX® powdered steel for the extreme edge retention, high strength, and toughness a hard-use knife demands. High wear resistance in a steel usually means low corrosion resistance. Not with ELMAX. With this advanced steel, you get both properties—which makes it an excellent blade steel. The ELMAX blade rolls out of the handle on the KVT ball-bearing system. With KVT, a series of ball bearings surround the pivot point so blade deployment is rapid, incredibly smooth, and your blade is ready when you need it.

The handle is 3-D machined G-10 on the front, and lightweight, strong 3-D machined titanium on the back. The titanium frame lock, with lockbar stabilizer, ensures a rock-solid lockup every time. To ensure this big bear of a knife carries at a comfortable weight, ZT has skeletonized the liner and machined pockets in the titanium handle and frame lock, too.

And to top it all off, the 0561 is equipped with ZT's new deep-carry pocketclip and Quad-mount system for tip-up, tip-down, left- or right-handed carry. The 0561 features a flat dark earth G-10 front handle scale.

Basic specifications, also from KAI :

A few notes on this one :

In regards to the edge thickness, it was a little heavier from the first owner (Kyley Harris) as some attempt was made to reduce the stock thickness in the first sharpening so it was reduced by a few thousands.

Stock cutting

This knife came with a low grit finish, optimized for slicing :

On 3/8" hemp :

Again the significant decrease in force shows the high slicing aggression.

On carving wood compared to the #1260 Mora : through ten points on on some 1x0.5" pine making 2" points with light force (10-30 lbs) :

Both knives are similar with light force which would be expected as the edge angles are similar and for shallow cutting that is the main factor/influence. However there is a huge difference in ergonomics as the Mora is very comfortable in extended use as it fills the grip well and has no high pressure points. It isn't an ideal whittling knife though as it is a bit too thin in the top of the handle - but again this is a small refinement only.

However through ten points on on some 1x0.5" pine making 2" points with heavy force (50-70 lbs) :

The very high relative advantage on the deep cutting just shows the influence of the very thin edge due to the regrind. Now while the performance has dramatically increased, this isn't a practical advantage for long term use because the handle has an extreme level of abrasion as the jimping is extreme sharpen as it isn't at all chamfered.

Utility

The ZT 0561 as a utility knife fails in regards to cutting and handling due to the following :

Compared to a Swiss Army knife it fails strongly which can do the same work faster with less effort. Even a Paramilitary is more capable due to the more slender point which starts the cuts with less force and easily does scoring type work. However all of the same aspects which reduce the performance here increase the ability for :

In regards to heavier use :

An attempt to pry it off with the Sanrenmu SRM 710 failed as the blade too a permanent bend before the wood was more than 1/8" free however the blade stock on the ZT 0561 is much thicker (0.155" vs 0.1" and it is also much wider so it is almost three times as strong. It was able to pry off the wood but there were two problems :

Thus even though it was more capable for prying it was not safe, effective or really functional to do so as the design isn't consistently capable.

Field

The ideal wood for many applications outside looks like the picture on the right :

Often it is very trivial to break just by walking on it or snapping it in the crook of a tree, under a log, or just across your knee. It works very well for small tools, is excellent for burning and generally works well for most construction taking into account that it is often much weaker than the cross section would imply as it often cracks after severe drying.

However it is not always easy to find that when you need it. Locally there are a number of very nice types of vegetation which can be easily harvested and some of them like Alders

They are also :

The ZT 0561 easily chops through the Alders up to 1-2" thick with just 1-2 chops. It also readily clears off the branches, able to sweep them off with multiple branches in just light wrist pops. Now it is possible to just slice them off but it takes :

There is an argument that such work is abusive and such work is not intended for folding knives, however if knives such as this are not used for such work then they are fairly useless design wise. If all they are to be used for is light cutting then they are readily outperformed by knives which are lighter built such as the Paramilitary or on the extreme end Havalon Piranta Edge. This is one of the main issues with larger folding knives which are obviously built for such work. If they are not to be used for work which has significant loads and impacts such as this light wood work then what exactly are they supposed to do because they make fairly poor light cutting tools.

In general this one has the :

To do such work well, though again the ergonomics are an issue as the clip is not well positioned for maximum comfort, more details are in the video on the right.

Grip

Ergonomics : the 0561 has the general flared to end handle shape which was popularized by Strider which has a loose fit to the handle but is focused almost entirely on the index/thumb and pinky part of the grip and makes only light to loose contact with the ring/index finger and center of the hand.

The clip while decent does not have the high ergonomics of the better clips which are either :

The largest issue is the extremely aggressive jimping which is so sharp that as noted in the picture on the right, even one heavy cut will produce visible signs of extreme high pressure points and "hot spots".

Gloves will however solve most of the problems with the abrasion level. A quick check on cotton gloves and 500 slices into birch hardwood flooring with heavy force (50+ lbs) showed that it was workable for that level of work however there were a few interesting observations :

Now these gloves are very basic and inexpensive. They are in fact so low a cost ($0.50) that locally most people treat them as disposable, however for more expensive gloves the level of abrasion from the jimping may be a concern.

Versatility : the handle versatility is very low which is discussed in detail in the video on the right. In particular the following are very uncomfortable :

The two which are workable are :

But these are at most not uncomfortable rather than comfortable.

Security : the handle is only lightly shape indexing or contouring through the index finger choil which is very grip restrictive as it only works well for hammer style grips.

In general the security is very high due to the very sharp jimping/ridging which is left very square edged, not chamfered. As shown in the picture at the right, even at 5X magnification there is no rounding to the edge, it is still very squared. This is so much so that it can easily be used as a rasp on woods.

In short, without gloves the handle is likely to be considered extremely abrasive.

Durability : the handle is made from G10 and Titanium and is thus extremely strong, tough and chemically and temperature resistant. The only real concern is abrasion which is mainly cosmetic.

Lock and Mechanicals

The ZT 0561 uses a integral lock, a modification of the walker liner lock which uses one of the scales as the lock bar. Those locks are in general prone to issues with :

In general this one has none of the common problems and has even been subjected to extreme use by the previous owner with enough impact to shear off a piece of the lock face which just induced a little vertical play.

It also uses instead of washers a ball bearing system which has the distinct advantage that it will not jam under even an extremely tight pivot as of course the bearings just roll in the housings. There are a few concerns though for long term use such as contamination and how it would effect the bearing system because the bearings are in a plastic housing and are not nearly as rigid and durable as standard washers.

Sharpening

The ease of sharpening of this knife was radically effected in the positive by the regrind by cKc Knives (Kyley Harris) which significantly thinned the edge as noted previously. However as shown in the image at the right there is a significant issue in sharpening as the edge doesn't form clean.

The image shows the edge formed off of an 8000 grit waterstone however the apex does not end in a crisp and even line but instead has jagged irregularities which are a significant problem which can indicate issues with :

The edge was reset and brought up to a 600 DMT finish (25 microns) but again it didn't form clean. As noted in the picture on the right you can see :

After some cardboard cutting which dulled the edge completely and then resetting the edge and taking the edge up to a 3000 grit (5-6 microns) the problem revealed itself again in the same manner :

These would persist even after applying a 45 degree bevel and removing it three times.

After further sharpening the behavior changed and the chipping and fracturing started to reduce but it was replaced with :

As noted in the image on the right there is a shadow on the edge (this is about 1-2 microns in width) which is very difficult to remove and forms easily. This is not surprising as all that is happening is that the initial chipping was likely caused by the common water quenching in sharpening and once that damage is removed (which is concentrated at the very apex) the steel moves into the part that is just heat drawn (hardness reduced) and possibly almost micro-annealed so it tends to produce burrs easily.

Edge Retention

The initial edge retention was extremely poor. After even just a little wood work (the stock work against the #1260 Mora) there was little to no edge left. However more critical, the picture at the right shows the real problem as the edge shows significant :

This is one of the common signs of blown aus-grain however it can also be caused by over heating in grinding which can cause temper softening and micro-cracking from water quenching.

Some cardboard cutting showed that the problem persisted even after the edge was destressed and then reformed to a 600 grit DMT finish. As noted in the pictures on the right the edge starts to very quickly show :

It is never a good sign when both of these happen together.

Finishing the cardboard run the same effects are seen only much more extensive

The results of the Cardboard trial show that the steel is at best a Type I class steel. This is very surprising considering :

The last generally means more consistent behavior in all thermal processing including the heat treatment and more consistent behavior in use. The fact that the performance is so low initially points to a problem in the steel or how it was processed.

Results :

Fine DMT : Initial Run
Sharpness 15% 10% 5%
cardboard cut (m)
38 (9) 1.2 (2) 4.0 (7) 21 (5)

All of the above is obviously showing signs of significant problems with the steel. A quick scan of YT shows that other reports of the same problem are not uncommon Kevinthewiseone, gavko .

However subsequent runs did show improved improvement, the average doubled over the first run and was enough to show that it had at minimum of Class II level performance for abrasive edge retention.

Fine DMT : Subsequent Work
Sharpness # runs 15% 10% 5%
cardboard cut (m)
38+ 3( 4) 3 2.0-0.1 (0.3) 7.2- 0.3 (1.2) 43- 2( 9)

This shows that most likely that the problems initially were most likely caused by the edge being over heated and water quenched in the initial grinding. This unfortunately is too common when manufacturers switch to using high carbide steels without the experience to use them effectively.

They do some combination of the following to try to save costs and time :

All at the cost of the consumer.

Steel

Elmax is a Mould steel made by Bohler data sheet :

Uddeholm Elmax offers a possibility to make long-life, low maintenance moulds for the best overall moulding economy.

It is another curious steel to use in knives as its properties are not those suited to taking or holding a fine edge. It is often extremely highly promoted :

The performance of Elmax is far superior to S30V. Elmax is much tougher and has far better edge holding. It is also easier to finish. The third generation powder metallurgy AKS.

However there is little to no physical data cited to support the claims and interestingly, frequent problems are commonly reported with poor performance of Elmax in an area where it should excel which is cutting abrasive materials JDavis rope cut. However it is likely that many of these problems are due with the edges being overheated as people have reportedZT visible scaling and just really poor edge retention Gavko which have improved quickly after repeated sharpening.

As noted previously, this is most likely due to Elmax simply having a very low grindability due to the high carbide volume and thus being over heated by low quality of worn belts or both.

This one had the same issues :

As shown in the picture at the right which was the result of just light utility work cutting woods and plastic. The edge will readily fracture to a depth of about 0.002" essentially giving it no effective fine edge retention. These problems did gradually reduce but it took multiple sharpening sessions and considerable loss of steel.

Overview

Overview :

Comments and references

Comments can be emailed to cliffstamp[REMOVE]@gmail.com or by posting to the following thread :

and/or the YouTube Playlist.

Most of the pictures in the above are in the PhotoBucket album.


Last updated : 23/05/2013
Originally written: 07/05/2013
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