

⚔️ Own the blade that serves the Navy — be mission-ready, always.
The Ontario 6141 MK 3 Navy Knife is a 6-inch fixed blade crafted from durable 440A stainless steel with a black oxide finish, delivering military-grade toughness and corrosion resistance. Designed for professional use, it features a molded high-impact plastic handle for a secure grip and comes with a robust sheath equipped with a brass belt hanger for reliable carry. This knife is the official issue for the U.S. Navy, combining heritage craftsmanship with tactical functionality.













| Age Range Description | Adult |
| Asin | B000UU7ZFS |
| Best Sellers Rank | #972,912 in Sports & Outdoors (See Top 100 in Sports & Outdoors) #3,591 in Fixed Blade Hunting Knives |
| Blade Edge | Plain |
| Blade Length | 6 inches |
| Blade Material | Stainless Steel |
| Blade Shape | Straight |
| Blade Type | straight edge |
| Brand Name | Ontario Knife Company |
| Color | Black |
| Customer Package Type | Basic Protective Sheath |
| Customer Reviews | 4.5 4.5 out of 5 stars (291) 4.5 out of 5 stars |
| Global Trade Identification Number | 00071721061410 |
| Hand Orientation | Ambidextrous |
| Handle Material | Plastic |
| Included Components | Sheath |
| Item Length | 10.75 inches |
| Item Type Name | Ontario Knife Co MK 3 Navy Knife |
| Item Weight | 1.1 pounds |
| Manufacturer | Green Supply |
| Model Name | 1061410 |
| Model Number | 6141 |
| Number Of Items | 1 |
| Orientation | Vertical |
| Part Number | 1061410 |
| Power Source | AC/DC |
| Product Care Instructions | Hand Wash Only |
| Recommended Uses For Product | Camping |
| Reusability | Reusable |
| Size | 6" |
| Special Features | Water-Resistant |
| Style | Fixed Blade |
| Theme | Sport |
| Unit Count | 1 Ounce |
| Upc | 730707310835 658804124752 071721061410 |
| Warranty Description | SEE MANUFACTURER |
User
Don't believe the ney sayers
If you are looking for a rugged survival knife or are into collecting military knives add this one to your collection. The knife is not as sharp as it could be out of the box, but, two thoughts here: first, for the price I can sharpen it myself; second, if you can't stone a blade, don't play with them. It is an original copy of the USN Mk 3 Mod 0, same with the sheath. The blade is 6 inches from the hilt to the tip and has a black most likely phosphate finish similar to post ww2 small arms finishes. The handle is of a hard plastic with a rubbery grip, typical military. The sheath with it's retaining clips fits the knife snug and will retain the knife until you are ready to deploy the blade. From visual inspection, I can not say if this is a full tang knife, the pommel is a not magnetic alloy along with the hilt but are both meaty. The blade is attracted to a magnet, but from my experience a lot of stainless is magnetic. Overall, this is a good knife at a great price.
User
A great knife but give some thought before using the sheath
This is a terrific knife. Many others have written of the virtues of this knife, so I won't be redundant. I can't believe I hadn't discovered this knife before. It is a nearly perfect military issue in features, form and function. The knife is great, but the sheath has pros and cons. Other reviews have mentioned the matter of the sheath requiring significant effort to insert and withdraw the blade as well as the spring blade retention significantly scraping the coating on the sides of the blade a little more each time the blade goes in and comes out. The retention springs inside the sheath hold the blade very firmly causing scrapes along both flat sides of the blade from about midway down the blade to the tip. I take it the sheath was designed and constructed for very secure retention. If it is desired to keep the blade from having the coating removed along the sides of the blade don't use the sheath that comes with the knife. If that doesn't matter, the sheath is very solid. One reviewer says the knife becomes easier to slide in and out of the sheath with repeated use. The sheath has a one inch wide nylon strap that serves as a belt attachment. There is a wire clip at the top of the strap intended to attach it to a military web belt. Just below the top is the retaining strap with a snap to secure around the knife handle. The strap has a loop so up to a 2 1/2 inch belt may be slid through it. The sheath is perfectly functional and well made if you don't mind the damage to the blade coating by using it.I like the knife and that's why I give it five stars. The sheath is an accessory, and it's up to the owner to decide whether to use it.Update: after scraping up half the blade using the factory sheath, I decided not to do that any more. Using a "Scotch Brite" scour pad I rubbed out the scrape marks and made both sides of the blade look the same. It removed very little of the black oxide coating. Now the blade looks almost new. I work with Kydex, so now the knife has a new sheath and a new look.
User
Solid as hell
A little backround on this blade. It is a US Navy marked Mk3 mod zero dive knife. Built strong and meant to last.ProsLooks bad assFeels solidGreat grip textureVery strong steelSolid enough to take a beating or to pound in a tent stakeConsThe steel on it is almost too hard, it doesn't arrive "knife sharp" and it took me a lot longer then it normally takes to put a truly sharp edge on it. The blade is very thick so using an auto sharpener for like a kitchen knife will not work. Once the edge is there I believe it will last almost forever but don't expect this thing to ever be truly razor sharp.The case comes with a standard military belt look attachments with regards to the "little hooks" and will require some modification to to fit on a normal belt to hang it from a vest.its not lightweight by any means so if your shaving weight this isnt gonna be on the list.All said and done it is a great knife and I love it. It will last forever and is a valuable peace kit if your outdoorsy. Its my knew primary field knife.
User
Great Knife - Useless Sheath
The knife is a USN knife which was issued to SEAL team members. Excellent all purpose knife designed for use in the water so resists rusting and corrosion. It is one of the best military knives ever issued, and many former vets can tell you how well it performed under adverse conditions. Compared to the Ontario Air Force Survival SP-2 knife, however, the MK 3 is a half inch longer but far less meaty in the blade and thus less sturdy, and in comparing the two knives, I prefer the SP-2, without denigrating the MK 3, because I think it is more versatile. BUT my REAL issue is with the sheath sent with this MK 3, and I notice that many other reviewers have also complained. It is EXTREMELY difficult to even put the knife into the sheath; it is that tight. In fact, it is potentially dangerous because the blade might slip in the attempt which could cause injury. AND every time you pull the knife from the sheath, you take the coating off the blade. Not sure what the guys who came up with this plastic sheath were thinking. But your black knife will very soon have a silver blade and a scratched one as well. Sheath is LESS than useless because it actually damages the blade. Have ordered a Spec.-Ops. Brand Combat Master Knife Sheath which some have said will fit this blade well, but that sheath costs 50% of the price of the knife.
User
Buy it while you still can!
You better buy this while you still can Ontario knife company has closed and all the workers let go. The Ontario name and remaining stock has been sold to another company their a distributor not a manufacturer. The new company is going to continue some of the offshore produced knives (Rat folders) and looking to keep US production on certain models probably Rat fixed blade etc. My guess is all the military knives and bayonets will be discontinued once the stock is depleted. I got the MK 3 from Amazon today and the quality looks fine it felt like it was dull as a butter knife but it sliced right through paper so it is sharp. The people complaining about the blade coating must not have much experience with this type of treatment lol besides it's made out of S.S.
User
Great knife
This is a heavy duty knife. Ontario Knife Company has ceased operations, so these will become hard to find in short order. This is the knife that has been issued to US Navy divers. It holds up fine in and out of the water.Dry it off and oil it before storing it.
User
pretty much agree with the previous reviews.....
To me, this is a good knife but perhaps a bit too expensive for overall what you get. The sheath does kinda suck, and i'm glad Amazon links what other people 'look at' when they view this knife, because that's how I saw that people buy a different sheath than what's provided, and I bought that sheath too (Ka-bar sheath). Long story short, I wasn't impressed with the original sheath. As for the knife, it has a good feel, nice and solid. The knife doesn't come all that sharp, so one really needs to sharpen it further. In fact, the top part of the blade is sharper than the lower part of the blade, which to me is odd. And yes, I agree with other reviewers that the saw aspect of this knife is really lame, and should have been a serrated edge instead. Overall, i'd say it's a bit too expensive for what you get, and I wish I would have done a bit more research into knives of this style, such that maybe I would have found the perfect knife at a lower price. Just cause it's apparently a 'Navy knife', doesn't make this, to me anyway, the perfect knife. But that said, it's not like it sucks. Get the better sheath, and be prepared to sharpen it further, and if you do that, then it'll be a great knife for you, even if it seems kinda expensive to me. Hope that helps.
User
One of the best knives I have ever carried!
This Mk3 has to be one of the very best knives I have ever been issued and carried while serving in the military. This knife is a full tang knife which has been tested by torturing, grueling and putting this knife through every imaginable scenario that those in the NSWF community could come up with! Which is why this knife was selected by the NSWF community chose this knife for their combat knife. As a River Rat, I had the upmost pleasure serving with the best of the best of the Navy's finest. And as a member of the River Rats, I had been issued one of these knives as well. I can say that I would trust this knife with my life, as I believe that the quality of this knife is one of the finest made knives I have come across!
User
Quality American Made Product
Solid and durable knife. I have heard that some of these knifes have arrived dull, however, the one I was received passed the paper and shaving test out of the box. There were slight imperfections at the edge of handle, something you wouldn't see in a SOG, but nothing major.
User
Excelente cuchillo
Se nota de excelente calidad, el que vende Amazon es original, en otros sitios son copias chinas de menor calidad.Tengo 3 años con el y sigue cómo nuevo.
User
Mal anders herum
Oft liest man ja von guter Ware und schlechten Händlern. Hier ist es mal andersrum.Zur Ware:Braucht man wirklich ein MK 3 Navy Knife? Klares Nein! :o)Unabhängig davon macht mir auch der Stahl der Klinge einen minderwertigen Eindruck. 1/5 PunkteZum Händler:Der Händler bekommt 5/5 Punkte! Von Anfang an super freundlich und zuvor kommend. Beim Import (die Ware kommt aus Amerika) beschloss der Zoll das Paket erst mal zu konfiszieren und Trouble zu machen. Der Händler hat sich um alle Angelegenheiten gekümmert und mich auf Stand gehalten. Nach ein paar Tagen war alles gut, ich hatte keine Scherereien und die Ware kam an. Top Kunden-Service!! Danke noch mal dafür :-)
User
Awesome Knife
very nice
User
and it's great! This knife is perfect for her duties on ...
I bought this knife for my Daughter so is in the Navy, and it's great! This knife is perfect for her duties on ship.
Trustpilot
3 weeks ago
2 weeks ago