why this product

Invented by German steel exporter Heinrich Kaufmann in 1867, the Mercator knife gained popularity in the United States following World War II, when returning servicemen brought the blades home from Germany. Among knife aficionados, the Mercator maintains a cult following for its utility, handmade quality and long history. A lockback mechanism ensures that the blade stays in place while in use. The heel of the handle holds a tin can opener. The helix construction corkscrew (meaning that the corkscrew is bladed throughout so that it cuts through the cork) folds out in the middle of the handle, allowing you to use it as a grip when uncorking wine. Finally, an awl (metal spike) is included for loosening knots and piercing holes in leather and fabrics. Because sometimes you need that extra belt loop hole pronto. The Mercator is immediately recognizable for the famous imprint on the black powder coated steel handle: K55K below an outline of a cat. The first “K” stands for Kaufmann, while “55” refers to the street number of the original head office. The last “K” refers to the German word for cat, katze.

use & care

A nail-nick (crescent shaped sliver on blade) makes the blade easy to pull out. A lockback mechanism ensures that your knife stays open when you need it to. Depress the steel lever at the handle of the knife to fold the blade back in. Check the locking notch of lockbacks regularly to ensure that it is working properly. Keep all sand and grit out of the knife and keep the mechanisms clean. Carbon steel knife blades are harder, have a finer grain structure and retain their edge longer than stainless steel, but they require more care.To properly care for a carbon steel blade, wash it with mild soap and dry thoroughly after each use. Never place in the dishwasher. A moist towel can be used to wipe your blade between use with different foods. This is critical when cutting highly acidic foods. With care and over time, a carbon steel blade will develop a deep gray or blue patina from exposure to different elements. This coating is similar to the seasoning of a well-used cast iron skillet, as it will protect the blade from rust and discoloration. This dark patina is the sign of a favorite, well-used knife. If your blade does develop rust spots, our Extra Fine Steel Wool Pad and a little soap should remove the rust, though it may also leave tiny scratch marks on the blade, so go gently. Clean knife and tool joints by applying an industrial lubricant or oil and scrubbing crevices with a toothbrush. Remember to keep your knife sharpened: a dull blade can be more dangerous than a properly maintained one.

production & design

Otter-Messer, a blade manufacturer based out of Northern Germany, absorbed the Mercator brand made famous by Heinrich Kaufmann in 1995 and revived the knife based on yellowed drawings of the original design. Though simple and functional, the narrow knife is made by hand and requires over 120 steps to produce. Otter-Messer was founded around 1840 in a traditional grinder’s watermill by the Berns brothers. The company name refers to the indigenous otters that live in the riverbanks and streams of Northern Germany. 

about the designer

German Steel Multi-Tool Knife (9" open)

Kaufmann Mercantile from New York, NY
You Get Free Shipping! This product qualifies for
free shipping. Details.
All options are required.
This item is currently not available.
Sorry, this combination is not available.

Carbon steel pocketknife with lockback blade, tin can opener, corkscrew with helix construction (no cork crumbs) and awl (metal spike) for loosening knots and piercing holes. Made in Germany since 1840. (more info)

More Details

  • Technical Specifications:

    Blade length: 4 inches long (9 cm)
    Body with knife extended: 9 inches long (22.8 cm)
    Body with knife folded: 5 inches long x 1 inch wide x ½ inch thick
    (12.7 cm x  2 ½ cm x 1.2 cm)
    Can opener:1 ½  inches long x 0.6 inches wide (3.8 cm x 1 ½ cm)
    Cork screw: 2 ½ inches long (6.3 cm)
    Awl: 2 inches long (5 cm)

    Carbon steel
    Powder coated steel handle

    Made in

  • Restrictions: Promotions cannot be applied to this product.
  • Dimensions: H 1.0 Inches x W 1.0 Inches x L 1.0 Inches
  • Product Code: V176000283339

Shipping & Returns

  • This item ships directly from Kaufmann Mercantile in Brooklyn, NY
  • Item is ready to ship in 1 - 3 Business Days. Delivery date will vary depending on your shipping address.
  • International orders may experience possible delays and take longer to arrive.
  • We accept complimentary returns within 14 days of receipt if the item is unused and in original condition.
AHA Guarantee

AHAlife is committed to help you live a conscious and inspired life.

Many of the items you discover here are exclusive to AHAlife, which is what makes our community of designers and artisans so special.

If you find one of our products anywhere else for less than it's being sold on our site, we will match it. No questions asked.

Our dedicated Concierge Team is here to help. Reach out any time at:

Monday through Friday, 9am to 6pm EST
Have Questions? Just ask our Concierge Team
Just Added
Introducing App
Just Added