Types of Can Openers on Pocket Knives

The design of pocket knife can-opener blades is usually a variation on a well-known theme of hook, lever, and cutting blade. Different manufacturers have developed different styles and multi-purpose blades that are more or less difficult to use. The simple pattern found in many Victorinox Swiss Army knives is still one of the best.

  1. History

    • Connecticut inventor Ezra Warner patented the first can opener in 1858 when cans were made of iron and sometimes weighed more than the food they held. Warner's opener was a bayonet-style knife with a curved blade and showed the basic design still used as a pocket knife blade. During the 1860s can technology was refined to thin metal containers, and clerks were no longer required to open containers for customers before they left the store.

    Offiziersmesser

    • One of the first multi-function pocket knives, the Offiziersmesser, invented by Karl Eisner of Switzerland in 1891, included a can-opener blade. The successors of Eisner's first knives became popular with American soldiers during World War II. Although G.I.s were issued a small folding can opener called the P-38, the Swiss invention more familiarly known as the Swiss Army Knife was much more versatile. Victorinox knives now have a world-wide market and nearly all include the can-opener blade.

    Types

    • Can-opener blades resemble bottle-opener blades. The bottle opener has no concave cutting edge and often has a squared tip that doubles as a screwdriver bit. Both can-opener blades and bottle-opener blades use steel hooks to grip the rims of cans or the lips of bottle caps. Can-opener blades are either curved or have an angled blade with a strong sharpened edge. By placing the hook under the rim of the can and the blade over the lid, the blade can be levered through the metal. Back the blade up and repeat, until all but a small hinge section is freed.

    Alternatives

    • Victorinox also developed a forward-cutting blade working on the same principle but using a convex cutting edge towards the tip of the blade for the penetrating work. Though more awkward for opening cans, this design exposed the cutting edge and made the blade useful for scraping and prying actions. The Wenger blade, in contrast, refined the can opener style and was a single-purpose blade. With a thin, sharp-hooked blade, the edge of the Wenger made short work of cans but was good for little else.

    Innovations

    • A newcomer to the market, the Leatherman multi-tool includes a stout and ingenious improvement to the pocket-knife can-opener blade. A folded steel blade with a can-opener cutting edge on one side works similarly to the Victorinox version, but the channel of the folded steel follows the edge of the can and helps control the action. The simplest can opener is no doubt the straight knife blade. Although no one can safely recommend it, a strong blade is still the can opener of last resort.