---
product_id: 1446980
title: "Ontario 6141 MK 3 Navy Knife (Black), stainless steel"
brand: "ontario knife company"
price: "R1636"
currency: ZAR
in_stock: true
reviews_count: 10
url: https://www.desertcart.co.za/products/1446980-ontario-6141-mk-3-navy-knife-black-stainless-steel
store_origin: ZA
region: South Africa
---

# Black oxide finish for stealth & durability 6-inch 440A stainless steel blade Includes rugged molded plastic sheath Ontario 6141 MK 3 Navy Knife (Black), stainless steel

**Brand:** ontario knife company
**Price:** R1636
**Availability:** ✅ In Stock

## Summary

> ⚔️ Own the blade that serves the Navy — be mission-ready, always.

## Quick Answers

- **What is this?** Ontario 6141 MK 3 Navy Knife (Black), stainless steel by ontario knife company
- **How much does it cost?** R1636 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.co.za](https://www.desertcart.co.za/products/1446980-ontario-6141-mk-3-navy-knife-black-stainless-steel)

## Best For

- ontario knife company enthusiasts

## Why This Product

- Trusted ontario knife company brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Precision 6-Inch Blade:** 440A stainless steel with 49-54 HRC hardness for sharpness and edge retention.
- • **Stealth Black Oxide Finish:** Resists corrosion and reduces glare for tactical advantage.
- • **Ergonomic High-Impact Handle:** Molded plastic with rubberized grip ensures secure handling under pressure.
- • **Military-Grade Craftsmanship:** Trusted by the U.S. Navy for unmatched reliability in the field.
- • **Secure Sheath with Brass Belt Hanger:** Rugged retention system keeps your blade ready and accessible on the go.

## Overview

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.

## Description

The Ontario Knife MK3 Navy knife is the current military issue knife to the U.S. Navy. Situated in New York State's scenic Southern Tier, Ontario Knife Company produces one of the most comprehensive, wide-ranging product lines in the cutlery industry today. While being a worldwide supplier, the Ontario Knife Company is also a major supplier to the U.S. Government and its military. Ontario has built its reputation on a heritage of uncompromising craftsmanship, quality materials and components, and a steadfast commitment to its workforce. Black oxide finished stainless steel blade. Molded high impact black plastic handle. Includes molded plastic sheath. Blade has a hardness of 49-54 HRC. Sheath is equipped with a brass belt hanger and loop. Note: These knives come with an application of oil to protect the finish of the blade during storage and transport. Once that oil protectant is removed with a cloth, the knife looks good.

Review: 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.
Review: 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.

## Features

- Made of 440A Stainless Steel
- 6 inch plain edge blade
- Knife Open Length: 10.75-Inch
- Weighs 10 ounces
- Knife Closed Length: 3.3-Inch

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B000UU7ZFS |
| Age Range (Description) | Adult |
| Best Sellers Rank | #554,075 in Sports & Outdoors ( See Top 100 in Sports & Outdoors ) #2,395 in Fixed Blade Hunting Knives |
| Blade Edge | Plain |
| Blade Length | 6 Inches |
| Blade Material | Stainless Steel |
| Blade Shape | Straight |
| Brand | Ontario Knife Company |
| Brand Name | Ontario Knife Company |
| Color | Black |
| Customer Package Type | Basic Protective Sheath |
| Customer Reviews | 4.4 4.4 out of 5 stars (290) |
| Date First Available | January 2, 2007 |
| Global Trade Identification Number | 00071721061410 |
| Hand Orientation | both |
| Handle Material | Plastic |
| Included Components | Sheath |
| Item Dimensions LxWxH | 12 x 2.75 x 2 inches |
| Item Length | 10.75 Inches |
| Item Package Dimensions L x W x H | 12.2 x 3.39 x 2.13 inches |
| Item Weight | 1.1 Pounds |
| Manufacturer | Green Supply |
| Material | stainless steel |
| Model Name | 1061410 |
| Model Year | 2012 |
| Number of Items | 1 |
| Orientation | Vertical |
| Package Weight | 0.53 Kilograms |
| Part Number | 1061410 |
| Power Source | AC/DC |
| Product Care Instructions | Hand Wash Only |
| Recommended Uses For Product | Camping |
| Reusability | Reusable |
| Size | 6" |
| Special Feature | Water-Resistant |
| Sport Type | Hunting |
| Style | Fixed Blade |
| Suggested Users | unisex-adult |
| Theme | Sport |
| UPC | 730707310835 658804124752 071721061410 |
| Warranty Description | SEE MANUFACTURER |

## Product Details

- **Age Range (Description):** Adult
- **Blade Material:** Stainless Steel
- **Brand:** Ontario Knife Company
- **Color:** Black
- **Handle Material:** Plastic
- **Included Components:** Sheath
- **Model Name:** 1061410
- **Recommended Uses For Product:** Camping
- **Special Feature:** Water-Resistant
- **Style:** Fixed Blade

## Images

![Ontario 6141 MK 3 Navy Knife (Black), stainless steel - Image 1](https://m.media-amazon.com/images/I/51PwFsLwQNL.jpg)

## Questions & Answers

**Q: is this knife "waterproof",  or will it rust in water with chlorine in it?  (pool)**
A: Tony V. gave a great answer.  First, there are many different types of stainless steel, all with different properties.  

First, understand what "stainless steel" means.  It does NOT mean absolute resistance to corrosion (rust). The metal can be attacked by oxidizing agents. 
"Stainless" only means that it "stains less" than other ferrous metals which are reactive to oxygen, chlorine, salts, etc.  Gold is one of the few metals that is relatively inert. 

Many surgical instruments and cutlery is made with 440 stainless steel.  To have further resistant to rust, 304 stainless steel is used.
For the most corrosive environments, such as marine fittings exposed to seawater, 316 stainless steel is used.  But there is a trade of in other properties. 
So yes, you have to care for any good knife if you want it to last and keep an edge.  Carbon steel readily discolors and easily rusts, but it takes an edge and holds it better than stainless steel. 

Buy the best knife that you can afford, for the qualities that are most useful to you. 
And then take care of it, and it will serve you well.  Take it for granted, or neglect it, and it's going to go sour on you. 
Treat your knife with respect, and it will probably last longer than your marriage.

**Q: What is the current quality of the knife? Does the sheath scratch the blade?**
A: The overall quality is excellent. I own 22 different knives in this same class and this one is my "go to" knife. Over time, Yes, the sheath will wear on the blade and dull the black finish. Two ways you can prevent this...1.) buy a leather or nylon sheath...or, 2.) keep the blade lubed. The dulling of the black finish does not affect the performance, durability, or functionality of the knife.

**Q: What is the difference between this model, 8668, and the other one, 8604?**
A: 8604 was the old OKC # of the original knife before the Randall Adventure Team got involved with the knife and the knife got the new designation of RAT-7.

**Q: Is the bolster/guard made out of metal or is it plastic?**
A: The guard is made of metal. The handles are plastic.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Don't believe the ney sayers
*by B***N on January 27, 2020*

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.

### ⭐⭐⭐⭐⭐ A great knife but give some thought before using the sheath
*by D***Y on October 6, 2016*

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.

### ⭐⭐⭐⭐ Great Knife - Useless Sheath
*by L***D on February 4, 2024*

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.

## Frequently Bought Together

- Ontario 6141 MK 3 Navy Knife (Black), stainless steel
- KA-BAR Full Size US Marine Corps Fighting Knife, Straight

---

## Why Shop on Desertcart?

- 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016
- 🌍 **Shop Globally** — Access 737+ million products across 21 categories
- 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price
- 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members)
- 🔒 **Secure Payments** — Trusted payment options with buyer protection
- ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews

**Shop now:** [https://www.desertcart.co.za/products/1446980-ontario-6141-mk-3-navy-knife-black-stainless-steel](https://www.desertcart.co.za/products/1446980-ontario-6141-mk-3-navy-knife-black-stainless-steel)

---

*Product available on Desertcart South Africa*
*Store origin: ZA*
*Last updated: 2026-03-06*