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P-38 U.S. Military Can Opener

rated 4.5 of 5 stars
photo:   P-38 U.S. Military Can Opener kitchen accessory

This is one of those rare opportunities that someone like myself can bring an old invention used in the Military for decades and share it with the outdoor camping, hiking, climbing community, most of which will be learning of this amazing invention for the very first time.

I expect that this review will be the most popular of all my gear reviews. Not from anything I say...It is just one of those inventions that once you see it you are going to say I have to have it.

The P38 can opener is the lightest and smallest, most durable, multi-use can opener of all time.

There is no reason why every man, woman, and child should not be wearing this on their keychain or strapped to their backpack around the world. Yeah, it's simply that amazing.


  • Lightest can opener in the world
  • Smallest can opener in the world
  • Extremely durable
  • Can be put on keychain/backpack
  • Costs less then $1 dollar
  • Has been used for over 100 things
  • Can be used w/right or left hand


  • You're hearing about it for first time
  • You don't own one yet
  • Why didn't I have this on my last trip

     Originally designed by the U.S. Military,  the original P38 can opener

P38 Military Can Opener

The  P38  Military  Can  Opener- originally developed in 1942


Dimensions: 1.5" long , 0.70" wide

Weight: 0.16 oz.

Material: Stainless steel 

The P38 Military Can Opener, also known as the John Wayne by the United States Marine Corps because of its toughness and dependability, is an ultra lightweight and versatile manual can opener. It can be placed on a keychain, on army dog-tag chains, clipped to your backpack or even a zipper, and even small enough to fit in your wallet.

  1. Can Opener 
  2. Bottle Opener
  3. Box cutter
  4. Screwdriver (small Philips and flat head)
  5. Prying Items open (paint can for example)
  6. Striker for flint or ferro rod
  7. Wire stripper
  8. Letter opener
  9. Seam Ripper
  10. Cut fishing line
  11. Can even be used to clean fingernails

To use the P38 Can Opener one first rotates the cutting point from its folded position to its slightly over 90 degree position (90-95 degrees  on average) with the P38 can opener in one hand and the can of food in the other. Now  one latches onto the outer rim of the can using the middle of the P38 where there is a slight indent and hook like piece.

Next you twist the P38 downwards into the can cutting into can. Next you twist the other direction the P38 to get it out of the can moving it forward slightly to cut into next part of can... Rinse and repeat until can lid is removed.

P38 can opener in open position


The P38 can opener in my hand to show its' small size



The P38 has been known to me since I was first able to comprehend words. My father and stepfather and both grandfathers (maternal and fraternal) were in the military. Having all the male role models in my life all being ex -military introduced me to the military life and military gear and way of doing stuff.

I can only think of one other amazing gadget, the permanent metal match, that I have multiple backups for. Both the P38 can opener and the Permanent match are so small, lightweight, convenient in a pinch, and inexpensive that I have them with me everywhere I go.

One of the reasons why (not only reason) people do not end up bringing can goods with them is that they need a way to open the cans and the traditional can openers are too heavy and bulky to add to their bags.

It is literally physically impossible not to have enough room to pack this. Many people that I know that have these even have them connected to their keychain, backpack zipper, or even around their neck. I have used these my entire life and they have especially come in handy at home when my electric can opener dies (when you get old you will be amazed how many electric can openers you have gone through over the years lol).

I especially found this useful on my trip to Europe. There were days I just didn't want to do takeout to save some cash for a meal and this little guy allowed me to buy some can goods at the local market.

For extreme lightweight camping for an overnight I brought my Esbit, Campbell's Chunky Beef Stew, and this P38 can opener and a ferro rod.

I opened the can of soup with this P38, then used it to cut open the fuel tab packaging, and then used the P38 on the ferro rod as a striker to light the fuel tab. Cooked the soup in its own can. You can't get much lighter weight wise.

I strongly advise to put a very small piece of duct tape over the blade and onto the other side to prevent accidental opening of blade if carrying on person.

There is also the P50 can opener. It is about 1/2 an inch longer and a tad wider with a longer cutting blade that can open a can in a few less rotations.

Source: bought it new
Price Paid: $0.50 cents

Well, it works, sort of...


  • Small and light
  • There are no alternatives
  • It works, sort of...


  • You often bleed while using it
  • Not the easiest way to get a lid off

One guy in the military said this item was "great if you like the taste of blood in your spam." That is about right.

A previous reviewer noted that the new model has a clip to retain the blade in a semi-fixed manner. Maybe, but I am not going to go putting it into my pocket anytime soon. In a pack you need a rigid container like a film can (and nowadays, where do you get one of those?). The film can adds to the bulk if not substantially to the weight.  I used to use a thin strip of duck tape to hold the blade down and keep it in a small nylon sack with other small possibles. I suppose you could also probably use a rubber band, which would also eliminate tape gunk in your food.

So, the item in any permutation is not exactly a miracle of efficiency, but in short, what is the alternative if you foresee any chance of needing to open a can? Some, although not all Swiss army knives have what claims to be a can-opener blade, but they make this old GI can opener look like a miracle of efficiency. 

Mostly these days I do not go out for more than a couple of nights and can pretty much predict not to have to open a can. I do not carry a can opener any more, but for the thru hiker, unless you are prepared to use your knife, this is the only option. I guess in those circumstances I would still use it.

Oh, one final point. The ones made by Coghlan's are larger than the true GI openers (which I am told are no longer manufactured). However as the previous reviewer noted, generic after-market openers (like Coghlan's) are unreliable. I have had them fall apart in my hand mid-can opening.

Afterword: The supermarket where I do much of my food shopping just began carrying half cans of things like corned beef hash. The store is a common supply stop on the AT and is generally mentioned in the guidebooks, so I guess that it may be a nod to the thru hikers that supply there commonly during warmer weather. I wonder how many will have an operative can opener in these latter UL days? Still there are a lot of calories in some canned foods if you can get pass the weight of the initial carry. I often see thru hikers sucking down weightly foods just outside the supermarket. After four months of walking I would probably kill for a meal of canned hash, spam or stew.  Canned meats as bad as they are, beat dried and freeze dried all to Hell. Oh and one further note...supposedly this item cost the US government $250,000 to develop. 

Source: bought it new
Price Paid: next to nothing I think

Likely to hurt your hand if you don't file the corner.


  • Small
  • Cheap


  • Poorly made

There are several current versions of the P-38. Some people say that the ones stamped with "US Shelby" are the real deal, but the Shelby company that used to make P-38s for the military no longer exists and what you're getting these days are likely Chinese copies. I don't believe sellers that say otherwise.

There seem to be an unlimited number of these available new and they're unlikely all surplus. Amazon should require sellers to show their receipts. There are Chinese factories that will stamp whatever you want on P-38 can openers and they're far from military spec.

I've found the corner by the hole on those stamped "Shelby" to be sufficiently rounded on only about half. If you get one that's not rounded by the corner, you can try fixing it and risk ruining a file on the carbon steel or just deal with the pain in your index finger when you use it.

The one pictured says MIL-J-0837, not Shelby. I've tried these too and they're arguably even lower quality than today's Shelbys, their only redeeming quality being that they all have round corners by the hole. This number was stamped on a version that was actually used in the military, but like the Shelby, these are likely not mil spec P-38s, just poorly made copies.

The filing job these require is easier than on the Shelbys because there's less material you need to remove. You have to file the edge at the corner by the hole to remove a burr that could hurt your index finger, and you should probably file the face of it in the same corner. And the blade is impossible to open the first time by hand. And the blade over rotates so you may have to position it in the right spot once you place the P-38 on the can.

Some people complain that they get cut when they open by themselves. I keep mine in a closed key case and I use a version with a blade lock so I never had a problem.

Source: bought it new
Price Paid: .40 each for 100

Swiss army of the can openers.


  • Stainless steel
  • Very sharp
  • Easy to handle
  • Weigthless


  • None


Actually, it was a gift from a fellow eBay seller many years ago. I've kept it all these years in a slit like pocket of Leatherman Core's cordura pouch. Since it is relatively small and almost two-dimensional when folded, it can be carried in anywhere.

It's been a long time since I dropped my canned food from my backpack, but hey, you never know when an unexpected grab-and-go trip happens and all you can do is buy a few canned food from the market and go. They are always good if you do not wanna go preparing your meal(s) on the field, anyway.

I was checking my tool to see it functioned flawlessly when this can opener dropped from the pouch in front of me. I grabbed it and wanted to give it try. I was looking for a gas can or something similar when I realized my wife emptied a 5 liter olive oil can and put it in the recycling bin. I immediately grabbed the can and tried the can opener on it.

The handling was so smooth and comfortable that I was just carried away cutting the three edges with ease. Right about to turn the final edge did I realize to make a video. At the end of the entire cutting cycle, the edges were so nicely cut that I did not feel any need to wear gloves when handling or holding the can through the cut edges.

A very nice and handy tool from the U.S. Army. Every outdoor enthusiast should have one. I love it.


Source: received it as a personal gift

This item was originally designed for the US military. It's a simple tiny can opener, never needs sharpening, works on any style can (rectangle, round, oval). They cost about 50 cents for two at Campmor and other companies.


  • Made of steel,
  • Is super light
  • Works!


  • Sharp point on can pierce can be easily modified with a rubber band around the folded point.


Can't get much more detailed than I already have stated about it. Simple to use, one handed (actually one finger and the thumb), right hand only, but not sure, may be able to get one for lefties.

Note picture: It's as small as two pennies side by side, mine made in Canada. Maybe their military not ours.

Has hole to attach to a keyring or string, etc.

Source: bought it new
Price Paid: 50 cents

Great compact can opener from a different time.

I imagine the new ones, like the old, are cheap stampings. I carry the one my dad got in his Army days (1958-1961). He had that thing banging around on his keyring for 50 years, so maybe all the sharp edges got worn down?

Anyway, I've never had a problem just carrying it in my pocket, but if you did, just clip it to the outside of your pack and Bob's your uncle. Why overcomplicate things?

And... if you're getting bloody, you're doing it wrong. Never had a lick of trouble opening cans of with mine. Not to mention its other uses. It's a decent screwdriver in a pinch and you can use it for lifting pull tabs on cans, cutting open those little bags of peanuts you get on airplanes, etc.

Unlike a lot of tools, you can get this one through airport security. You could probably even sharpen an edge if you wanted, though the body is mild steel so it wouldn't hold up for long.

This item will open a can very quickly and easily.


  • Opens a can quickly and easily.


  • Small—could be easily lost or misplaced. Putting it on a key ring would solve this problem.

I used one of these (Army issue) to open C-Rations in Army Basic Training in the '60s. I could easily open a normal size can in half a minute or so. Easy to use. It takes a little time to get the hang of it, but when you get it there is no problem.

I have seen some people complain of rust. I never experienced a rust problem and I still have one that I got from a Vet friend 30 years ago that works great and has no rust.

They are small and handy and easily fit on a key ring. Great product IMHO.


I have used it on several occasions.

Source: received it as a personal gift

Will open cans for minimal weight.


  • works fairly well
  • Compact and light
  • Inexpensive


  • Strong surplus models hard to find
  • May have outlived its usefulness

I have a warm spot in my heart for the venerable P-38, much like the one I have for my old Trapper Nelson wood-framed backpack. It's a wonderful classic piece of gear that is of limited utility in the 21st century. I keep a P-38 in every vehicle, virtually never use them.

The problem isn't with the opener itself, but rather the chore it does. If you are backpacking (or even paddling and portaging) what the devil are you carrying cans for? If you are car camping, why not use a "real" can opener. There is a wide selection of processed "non-perishable" food available in boilable pouches that isn't any worse for you than canned goods. 

I have broken or bent the new cheapo (Coghlan's etc.) models in a half dozen ways, but they will work if you are careful. 

I suppose if you are not counting grams it might be worth carrying one into the backcountry. Never know when you might blunder into an unopened can whose contents you can't live without.

Source: bought it new
Price Paid: Can't remember, but less than a buck

No man or woman should be without one. Not everything has a pop top or a bag zipper. Only an idiot could cut himself/herself using a P-38.


  • Folds down small
  • Lightweight
  • Works
  • Low cost


  • None

I have had one on my key chain and with my backpacking stove since I left the military more years ago than I want to remember. It's the greatest invention since C-rations . :)

Source: Hell, I can't remember that.

A fine little piece of work. I hope the guy who invented the P38 got a huge bonus for it.


  • I've never bled using mine, just gotta get that opening rhythm down
  • It opens all manner of tin and aluminum cans


  • The cheap knockoffs, as mentioned, are worthless and don't work.

So, where do I carry mine that I've had since I joined the Army in 1974? Well, since my Swiss Army knife can opener doesn't work as good as a P38, mine is attached to that very knife. The little split ring at the one end holds it nicely. 

Oh, you can get originals at Army surplus stores, but they are getting rarer.

Source: They came with C Rations. Basically, issued.

I've had a P-38 on all my key chains for 25+ years.


  • Lightweight
  • Durable


  • Need to practice with it

I have a P-38 on all my key chains. Have had and used mine for 25+ years—very handy. Used on round and rectangular cans, and doubles in a pinch as a flat bladed screwdriver.

Originally got from a can of calcium carbide (for miner's lamps or carbide cannons). Essential gear!



  • Very portable
  • Light
  • Functional


  • May stick you in the leg if you attach it to a keychain.

I have a P-38 on every keychain I own. Some I bought and some were included in cases of C rations from the early '70s. The are ALMOST indestructible and having one can be very useful in the field or in the office.

Get one and learn to use it.

Source: received it as a sample, freebie, or prize (US Army)

Does the job it was designed to do.


  • Old school cool

Got mine in the Marines back when C-rats were on the menu.

Sometimes called a “John Wayne” we would anger the old timers by calling it a “James Dean.”

This is the ultimate post-apocalypse tool. You could be the hero when all that’s left is canned goods.

Source: Got mine in the Marines

Indestructible, handy.


  • Always works


  • Will put a hole in your pocket if you just toss it in your pocket

Opens any size can, seconds as a flat tip screwdriver, opens paint cans using the flat side to pry the tops off, like a can of Johnsons paste wax. All military personnel have shined floors with that stuff.

Civilian version is much larger and able to apply force easier.

Source: In case of C rations

Very handy also as a screwdriver.

I have carried a P-38 (stamped GG Green 1957) in my pocket since military service in 1965, never opened accidentally in my pocket to cause a problem. What's the problem?

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