If there ever was a folder that was best described as a hefty chunk of metal, Muscle would be it. Even though the blade isn't in the long category, just under 4" long, overall the knife has really wide blade and handle isn't small either. I got the knife from the bladeforums trade section, in Jan 2018. I was just broswing, looking for sometihng interesting and that thing popped up. Looked interesting enough, made out of the Bohler-Uddeholm M390 PM steel, so I figured why not. Contacted the seller and got it in a few days.
I haven't heard of Tashi Bharucha before, and this was my first knife from CKF(Custom Knife Factory) too. All in all, positive impressions. All other designs I've seen from Tashi Bharucha are definitely more on the exotic side, just like the Muscle is. That is actually fine by me, more interesting designs make it better, so long the exotic part of the design doesn't get in the way of the function of the knife. At least for the Muscle that's not the case. The knife cuts and handles quite nicely.
General
- CKF Tashi Bharucha design Muscle can be described as a large folder with a wide, drop point blade. Even though the Muscle does have considerable size and in general, is built like a tank, I'd still say it is an elegant blade. Muscle sports 125mm(~3.9") long blade, which is 39mm wide(some of my kitchen knives are narrower) and the handle is obviously longer. All that metal translates into considerable weight too, 231.7g(8.17oz) to be precise. That's almost as much as the Spyderco Tatanka Folding Knife which for the record has a blade full inch longer, although Tatanka does have a thinner handle and G10 scaled, not Titanium handle slabs, which I'd love to get done one day, but I digress. The Muscle was shipped in mint condition, at least I have not found any visible signs of use. Quality, fit and finish are very good. Everything is well machined, fits precisely, nothing wobbles, rattles or is loose. Blade is centered properly. Action is smooth, two row ceramic ball bearings do help, but it is a flipper and to flip the blade of that size and weight does take an effort, at least compared to other flippers, but nothing annoyingly problematic.The Muscle came in in the French flag themed, tri-color pouch and a few small accessories, including: a red cleaning cloth, CKF sticker, and a certificate of authenticity. The later stated that the knife was made on 10/20/2017 and its serial number was 349. Unfortunately, I have no idea how many of Muscles were made in total, but I can live with that ;) I've seen plenty of customized Muscle on the net, though it's all out of stock, sold out. I suppose nothing is preventing you from customizing yours.
Blade
- The blade on the Muscle folder is 125mm(~3.9") long, and really wide too, as mentioned above, it is 39mm at its widest. You can easily guess, that blade won't be a thin one either, and you'd be right too. It measured ~4.8mm thick using digital calipers. Like I said, it's a tank. The blade, I'd describe as a wide drop point, with very slight hollow grind, and it features a top swedge, although the swedge isn't aggressive enough to form a false edge. Thumbramp is also present, however it has no gimping. Compared to most other folders or even fixed blades, the thumbramp on the Muscle is positioned a bit forward. Typically I don't have to extend my thumb fully to engage it fully, but on this knife I do have to do that. Can't say it's bothersome or too inconvenient, it just is. Does help with the grip when needed. As for the finish, the blade I have has hand rubbed satin finish, which looks very smooth and even, no scratches or blemishes, which I do expect from the knife at that price.Blade steel on the Muscle - Bohler-Uddeholm M390 PM steel, is an excellent choice for the folder of this class, I mean high end class here. That's not to say I would mind seeing M390 PM steel in a budget folder or fixed blade though, but not likely to happen, not yet anyway. Still, Bohler-Uddeholm M390 PM steel is widely acknowledged in the knife world as one of the best choices for the knife blades, at least as far as the edge holding and stain resistance is considered. M390 PM steel isn't the toughest steel out there, it's much better suited for the folders and light use knives, and despite its respectable size and heft, I'd still consider Muscle and pretty much any folder a light use knife, definitely not for bashing through the concrete blocks and pry opening crates and jammed doors. As far as abrasive wear resistance and general edge holding goes, M390 PM steel is one of the better performers, definitely in the top category. M390 PM steel is a stainless alloy, however as I keep mentioning in every review, it will rust if neglected,still being a high carbon steel.
Sharpening
- In my experience, M390 PM steel works better with a coarse edge, which makes sharpening less time consuming, I typically stop with 800-1000 grit stone, something like Bester 700 Grit Super Ceramic Whetstone, King 1200 Grit Super Ceramic Synthetic Whetstone or diamond duosharps. Then depending on how I feel, I either use a plain leather strop, or a .50µm diamond powder charged strop, or if I feel like it, both, in succession. Gives very aggressive, coarse edge.As for the edge angle, for the light/medium use folder with the steel at 61HRC I use 15° per side angle. And because I sharpen most of the time freehand, the edge is convex. As far as the ease of sharpening is concerned, M390 PM steel is easy, or medium difficulty at worst. Typically hardened to 60-61HRC, it is way easier to sharpen than many other high wear resistance steels, especially at higher hardness like 64+ HRC.
Handle
- The Muscle folder features Titanium handle to reduce its weight, and given its size, that is a reasonable choice. The handle itself is about 127mm(5") long and it isn't exactly a narrow handle either, all that blade has to go somewhere, at least half of it :) The backspacer is also metal, and I'm assuming it is Titanium as well. The serial number #349 is stamped on the backspacer, closer to the handle butt. Handle slabs have fairly elaborate texturing, but it's well done, in that it provides good grip security and feels nice, without being too aggressive to become an annoyance during knife use, even during heavy use.Often, on those so called exotic knives, the handles are also exotically shaped which gets in the way of ergonomics and comfort. Not this time though, the Muscle handle is reasonably comfortable and doesn't cause issues during light medium use, I mean blisters and hotspots. I did use the knife for longer times, as usual that means cardboard cutting sessions, and I never had to resort to gloves, it was comfortable during the session.
The clip is matching the handle in terms of design. Titanium, same texturing, single screw is used to attach it to the handle slab. I haven't tried it, but from the looks of it, it can easily be moved to the left side for the left handed carry.
The Muscle folder uses the framelock mechanism for locking. One interesting part is that the lock bar appears to be two piece, inner bar has textured slab screwed on top of it. I'd think(or hope) the bar was the steel, but the description on the CKF website says frame material is Titanium, which isn't exactly the best news in terms of lock bar longevity. Titanium isn't the most wear resistant material, definitely less so that the steel blade it comes in contact with. There's a reason a lot of framelocks use steel bar at the top of the lock bar. As it is, for now the lockup is rock solid.
Usage
- I've been carrying the Muscle of and off, it's in my rotation list, given the fact that I've been collecting knives for a log time that list has grown considerably. However, given its size,and my habit of carrying the knives inside my pocket, vs. on the belt where it'd be way more convenient :) Still, carrying it inside the pocket isn't an issue in normal pants of shorts with normal sized pockets.Outside of the specific tests, I've been using the Muscle for menial tasks, opening boxes, which I do a lot of(circa 2020) due to the stupid pandemic and resulting lockdowns, food(carefully washing before that), occasional wire or rope. Well, as a software developer, I don't get huge variety of vital/survival cutting tasks. For a letter opener, Muscle is definitely an overkill, but definitely gets the job done :)
Testing
- The tests I did were primarily done to evaluate the knife performance, I've used M390 PM steel before, more than once, so I already had a pretty good idea what to expect from it, but to state the fact, it has really good edge retention with coarse edge. I have not done testing with high polish edge, don't really see a reason for now, but I might do in the future if I every find that reason :)Now for the tests, which was a battery of my usual cutting tests. I've mentioned above, the edge was at 15° per side angle, or 30° total if you prefer it that way. The edge was finished using 1000 grit stone and then stropped on .50µm diamond powder charged strop and then on plain leather strop. Actually, I did several runs of testing, mostly due to time constraints, and to reset, but each time the edge was restored, best to my abilities to provide same initial sharpness, to keep things consistent.
The edge retention test was mostly cardboard cutting test. Given the longevity, this is also a good test for
usability and handle comfort assessment. Again, that part - handle comfort, was good, no hotspots or blisters post
testing. Typically, the blades with hollow grind, they introduce extra drag when cutting thick mediums, but with
the muscle the radius of the hollow grind is very large relative to the blade width, or in other words, hollow grind
is very shallow, closer to flat grind, so there was no noticeable drag increase when I was cutting the cardboard.
Overall, I went over 800" of cardboard, checking edge sharpness every 100" The blade lost easy shaving
ability around 600"-700" mark, not completely but I could notice the difference and it's miss a hair or two.
However, after that for the rest of the cutting session, there was no noticeable edge degradation.
In case you are curious, I was using push cutting method, on the same spot, about 45° angle relative to cardboard.
The blade just glided through.
The edge restoration was very easy, I did about 10 strokes per side on a ceramic rod and just to be sure light stropping on a plain leather strop as well. For the next test I proceeded with wood whittling, which I mostly use to determine edge stability and strength. Although, with 15° per side angle I wasn't really concerned with edge damage, but was worth testing anyway, the expectations can always be wrong ;) I played with dry wood for about 15 minutes or so, sharpened a few sticks, performed the edge twist test, to be specific stuck the edge about 2-3 mm deep inside the wood and twisted the blade perpendicularly. The edge suffered no damage. I diligently examined the edge using 10x loupe. I didn't expect to loose any performance during that test, and the edge test confirmed my expectations. Good news in short.
The next test was wire cutting, which I did few days later, the next weekend to be precise. Steeled the blade a
bit, light stropping, 5 strokes per side and went with the test. As usual, next test is the wire cutting test. As
with the wood whittling, this is more on the edge stability/strength side. Although, to some extent also tests my
own skill to keep the knife strictly perpendicular to the wire to avoid the edge damage and deformation due to
lateral loads on the edge. You can guess, this is a push cutting test. Making a loop with the wire and pushing
through that is a sure way to screw up the edge. I observed numerous times, 63-64HRC and higher hardness won't
have any issues during this test, with the same set of wires,but for the blade at 60-61HRC the results can vary.
I've collected my usual set of the copper, aluminum, and steel wires, plus RG6 coaxial cable, which is a
complicated mix of copper core, plastic, copper shielding and more plastic.
The 15° per side angle edge survived the test just fine. Again, examination with 10x loupe didn't reveal any
edge deformation. So, that's a pass too.
And to finish the the whole thing I went with the nylon rope ¼ diameter. Mostly to test the edge aggressiveness, and with 1000 grit edge it was no issue to slice the rope, nor was the push cutting. Well, that was it as far as the testing was concerned, I didn't have any old carpeting and whatnot to do the rest, but I figure it was enough to satisfy my curiosity.