P38 Can Opener

The tiny, lightweight, P-38 collapsible can opener was developed during World War II, reported to have been a rapid 30 days design project in the summer of 1942 by the U.S. Army Subsistence Research Laboratory in Chicago, IL. The origin of the name is not clear, like the jeep. Some claim it required exactly 38 punctures around a can to open it. Others say it performed with the speed of a P-38 fighter plane. Whatever the case, it is clear this little device has to be considered one of the most perfect inventions ever designed for use in combat.

P-38 Can Opener
P-38 Can Opener.

According to Gy. Sgt. R. Lee Ermey of the History Channel Mail Call program, Marines in Vietnam called it a "John Wayne" because it was so sturdy and dependable. However, that name may have referred to the P-51, a larger version of the same design, used for larger cans. Whatever the name, the P-38 was a favorite.

Today in WW II: 17 Jan 1945 Soviet troops capture Warsaw from German Army Group A who had occupied the city.   

The Versatile P38 Can Opener

Most troops carried it on their dog tags. More than just a can opener, in time the P-38 acquired 1001 uses: all-purpose toothpick, fingernail cleaner, screwdriver, bottle opener, box cutter, letter opener, chisel, scraper, stirrer, etc.

For World War II veterans, and then Korean War and Vietnam vets as well, the P-38 is a souvenir, a bonafide historical artifact worthy of retention. Countless old soldiers still carry a P-38 on their key chain a half century after the fact, or preserve it along with other cherished items from the war.

The P-38 was finally phased out when the C-Rations, last of the canned meals, were replaced by MREs.

Click here to download a detailed article on the history of the P-38 Can Opener. The little can opener is often called "the Army's best invention".

Instruction Sheet for the P-38 Can Opener

Below on the left is a copy of an instruction sheet showing proper use of the P38 from a DoD specification MIL-O-20582A dated 28 November 1956. It gives the official name for the P38: OPENER, CAN, HAND, FOLDING.

Among many other details this specification states in Section 3.3.5 that "Marking for Identification" shall include: "The letters U.S. and the manufacturer's name or trade name..." Packaging is specified as an individual envelope which are then put in boxes of 1000 envelopes (for general use -- special purposes can differ). So if you pick up a P38 that is supposedly "genuine surplus" from the 1950s or so, look for the US and an individual envelope package, such as on the right just below.

P-38 Can Opener Instruction Sheet
P-38 Can Opener Instruction Sheet.

P-38 Can Opener Original package
P-38 Can Opener Original package.

39 Uses for the P38

This list of P-38 uses was compiled by Steve Wilson, MSG Proponent NCO, Dept. of the Army Office of the Chief of Chaplains, The Pentagon. It is posted at the Ft. Bliss Air Defense Artillery Museum among other places:

  •  1. Can Opener
  •  2. Seam Ripper
  •  3. Screwdriver
  •  4. Clean Fingernails
  •  5. Cut Fishing Line
  •  6. Open Paint Cans
  •  7. Window Scraper
  •  8. Scrape Around Floor Corners
  •  9. Digging
  • 10. Clean Out Groove on Tupperware lids
  • 11. Reach in and Clean Out Small Cracks
  • 12. Scrape Around Edge of Boots
  • 13. Bottle Opener
  • 14. Gut Fish (in the field)
  • 15. Scale Fish (in the field)
  • 16. Test for 'Doneness' When Baking on a Camp Fire
  • 17. Prying Items
  • 18. Strip Wire
  • 19. Scrape Pans in the Field
  • 20. Lift Key on Flip Top Cans
  • 21. Chisel
  • 22. Barter
  • 23. Marking Tool
  • 24. Deflating Tires
  • 25. Clean Sole of Boot/Shoe
  • 26. Pick Teeth
  • 27. Measurement
  • 28. Striking Flint
  • 29. Stirring Coffee
  • 30. Puncturing Plastic Coating
  • 31. Knocking on Doors
  • 32. Morse Code
  • 33. Box Cutter
  • 34. Opening Letters
  • 35. Write Emergency Messages
  • 36. Scratch an Itch
  • 37. Save as a Souvenir
  • 38. Rip Off Rank for On-the-Spot Promotions
  • 39. Bee sting removal tool (scrape off w/ blade)

Thanks to Sgt. Kenneth Lewis, Texas National Guard, for this reference.

Find More Information on the Internet

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