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Extrema Ratio Rao

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In Stock

Available for Delivery

Extrema Ratio Rao

test 1Extrema Ratio Raotest 2Extrema Ratio Raotest 3Extrema Ratio Raotest 4 Extrema Ratio Rao

Extrema Ratio Rao

18+ Age Restriction Icon

In Stock

Available for Delivery



Back Order Item

Please note that this item will be dispatched once in stock. We estimate that stock will be here in 4 – 6 Weeks


Extrema Ratio Rao

Extrema Ratio Rao



The Extrema Ratio Rao is not so much a knife as a feat of engineering. With the customary robust design and precision manufacture the Rao reaches heights of ingenuity never seen before in the arena of knife design. Purposefully crafted for the Folgore 185 RAO (Regiment Acquisition Objects) unit of the Italian Army it is required to perform in environments and over a period of time that most folding knives would not cope with.

The blade is made from N690 stainless steel with a testudo finish, tempered to 58/60 HRC. It is ingeniously double locked open or closed using a threaded hinge attached to the handle with an elastic lace and a slightly more conventional spring loaded, slide bar lock, making it one of the safest knives in the open position in the world. The grip of the handle is specially configured, anticorodal material whilst the extremely tough nylon sheath with leather interior, is designed to take the knife in the open or closed position. A diamond sharpener is also provided in the front pocket of the sheath which is compatable with MOLLE systems. Sheath colour may vary.


Code ER-04.1000.0141/BLK
Limited Edition: No
Brand: Extrema Ratio
Blade Material: N690 Stainless Steel
Blade Length (cm): 11.8
Blade Thickness (cm): 0.6
Closed Length (cm): 14.20
Overall Length (cm): 26.0
Handle Material: Aluminium
Lock Type: Button Lock
UK Friendly Carry:


  1. Worth every penny...Review by
    This is my first ER knife and is unlikely to be my last. Superb fit and finish, shaving sharp out of the box. I checked out a lot of reviews and I have to say that it has exceeded my expectations. It may not be the prettiest example of the Knifemaker's art, but is an excellent example of function driving form. When this beast of a folder is in your hands, it is utterly confidence inspiring. This isn't a collector's piece, it will be put to work and will form the core of a bug out bag. Excellent service as ever from Heinnie. (Posted on )
  2. Comforting do all knife.Review by
    Had mine for 5 years, used as PMC's knife in dusty desert conditions. Never failed, always razor sharp after a light hone (DMT pocket hone). Reassuringly heavy and solid cutting tool with no doubts on quality. Sheath is a brilliant design but would like to see survival design similar to ER Selvans knife. (Posted on )
  3. lynd66Review by
    This knife is built like a battleship. Very sharp out of the box. Initially I found the blade a bit stiff to open but soon found that you can loosen and tighten the screw with an Allen key. The locking system is very good and solid. It's a brilliant idea to Jane a secondary screw to lock the blade in position to convert a folder into as fixed blade. (Posted on )
  4. A unique knifeReview by
    One thing that really defines this knife is the sheath, its designed to hold the knife securely when open OR closed.
    I think the concept is - carry into "working environment" closed, open and lock the knife, carry it locked open then close and lock when reaching civilisation.

    I know a few other folders that also have optional "carry open" sheathes but the RAO executes the concept perfectly.

    I really like this knife, thanks for the tip Linda.
    (Posted on )
  5. UPDATEReview by
    After the problems I had with play in the blade in the first knife, I returned it and got another, Must of been unlucky, Now its a five star rating!!!!!! What a versatile tough knife, Would be hard pushed to find a tougher bushcraft/survival Folder than this!!!!

    (Posted on )
  6. Great Alternative to a Fixed BladeReview by
    This was my First Extrema Ratio Knife & wasn't sure if the quality would be so good,I ordered and can say the build quality and design is Great. This is as strong a Folding knife as you will get! It is the most realistic alternative to having Fixed blade knife for bushcraft type work. (Posted on )
  7. MRReview by
    This is an excellent folder and very versatile, looks great and performs great but will never replace a fixed blade, and for the premium cost of this folder extrema should really sort the play out in the blade, tighten screw so plays gone and the knifes hard to open, have a nice linear opening on the blade and no matter what you do it has play when you work it hard, quite dissapointed considering the price!!! (Posted on )
  8. amazing knfeReview by
    The knife is at the top game it blows a lot of my fixed blades away delivery was abit lenthy but it wasnt hennys fault but etrema ratio (Posted on )
  9. Wannabe hatchet...Review by
    This knife excels at tough chopping tasks like light bush clearance and basha making. Think of it as a folding Kukri. Better thought out than it first appears, hugely strong and well made! (Posted on )
  10. Extrema Ratio RaoReview by
    I nervously ordered this to replace a fixed blade and after receiving the knife I am delighted. Its strong, well made, and it is BIG. Well done Extrema Ratio for giving the convenience of a folder with the ruggedness of a fixed blade in one package. Oh, and well done Heinnie for the lightning fast delivery as usual. (Posted on )
  11. RAOReview by
    About as tough as a folder will ever get, by far in a league of it's own!!! (Posted on )
  12. Extrema Ratio RaoReview by
    Working as a Military contractor it is very important that I have a general utility knife that can stand up to the pressure I put it under.

    First impressions of the knife were simply fantastic; the pouch it comes in is very well made and will attach to any Molle system.

    Very few knives I have had would get a top mark of 5,but I had no hesitation in giving this top marks; well worth the money.

    As alway Heinnie delivered the goods within 24hrs of ordering; that's customer service.

    (Posted on )

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