Will
USA

Oct 11, 2025

Pros: Blade Material, Blade Sharpness, Ease of Opening, Handle Feel, Handle Material, Lock Ease of Use, Lock Type, Overall Quality, Weight

Cons: None

Comfortable Carry

Light,,thin,fits pocket,easy to carry all day.

Tom
Chicago

Oct 20, 2017

Pros: Weight, Ease of Opening, Handle Material, Blade Material, Overall Quality, Blade Sharpness

Cons: None

Otter K55 Mercator, Black

This is a fun knife to carry! It looks unique, which is its main attribute. The Mercator came decently sharp and easily took an even sharper edge. You get a fairly long blade for a folder and the back lock is nice and solid. Being a lock-back knife less pocket lint gets into it, Which is a good thing because there’s no pocket clip (which might deter some from EDC). However the knife is also nice and light so it’s unobtrusive in the pocket. There’s a nice clip ring at the end which also helps keep the blade in when folded back. After researching I don’t really believe that this knife was standard German army issue in WWII but it was quite popular at the time for purchase among both civilians and soldiers and holding it does evoke a historic feeling. Not that I was for that side of course but German engineering has always been respected and to hold this knife is to hold something from another time that was simple yet fulfilled its purpose well. It also looks cool but not scary if one had to open it in a restaurant to butter one’s toast. I’m loving this purchase and Thank You Knife Center for offering it!

Jim D.
rochester, ma.

Jun 24, 2011

Pros: Weight, Overall Quality

Cons: None

love this knife,had one as a kid. lightweight and flat. slips in back pocket without notice until needed. keep on in pocket of every jacket.

Arnie
manorville ny

Sep 18, 2025

Pros: Blade Material, Blade Sharpness, Ease of Opening, Handle Feel, Handle Material, Lock Ease of Use, Lock Type, Overall Quality

Cons: None

very thin and sharp out of the box

Had one of these years ago, they were five bucks in the late 1960"s but still have the same quality

Valky
Augusta, Ks

Jun 11, 2022

Pros: Blade Material

Cons: Weight

old reliable

This is the knife I keep in my shop. I think I paid $20 for it back in the day. It's sharp from the get-go, sturdy as hell and can take about any abuse you can give it. It's a top quality no frills work knife that can handle any task that requires cutting.

Mike
New York

Nov 30, 2015

Pros: Weight, Ease of Opening, Blade Sharpness

Cons: None

Happy to Find That These Still Exist

I am a printing press man and no knife fits our occupation better than this one. We use these knifes in prepping the rolls of paper, cutting jammed paper out of the press, making the lead up tapes, cutting bundling twine, etc. The knife has a thin profile that allows it to fit in your pocket unlike the buck 110 which you have to wear a sheath which if you ask any press man you do not want things hanging off your body that can get caught. These knives take a beating the paint may wear off but it works day after day. Back in the day the paper companies gave us these. Then they disappeared the only ones were a cheap Asian copy that were terrible . I am so glad to see that you can get the real German ones again. Give it to the right person and you can make these razor sharp. You can go through paper like a lazer beam

Reg
New Zealand

Jun 12, 2012

Pros: Weight, Ease of Opening, Handle Material, Blade Material, Overall Quality, Blade Sharpness

Cons: None

An excellent EDC knife. Don't bother with the non-stainless version, this stainless one can easily be made razor sharp and holds its edge fairly well. Locks up tight, and if it gets loose you can always tap the pivot rivet with a hammer and it's tight again! So is adjustable and the spear pt blade is a simple emergency combat design. We used to call these possum skinners in NZ years ago, but I don't think they had a lock. But many possums were skinned. The katze (German) design is classy.

Martin S
new york, new york

Jun 07, 2012

Pros: Blade Material

Cons: None

Excellent knife, great service.

Jo
NY

Jul 20, 2021

Pros: Weight, Ease of Opening, Blade Sharpness

Cons: None

K55 Mercator

Just received this and think it's great. Came razor sharp and as other commented, it disappears in your pocket b/c it's so slim. I love the classic appearance as well, and feels great in the hand. The fit / finish is really good as well, but note there are two edges on the spine of the knife that are a little rough. Not sure if the steel was rough or if it's how the paint dried......may take a nail file and see if I can smooth out. Great knife all things considered especially given the price point.

Irv
Kansas

Mar 07, 2013

Pros: Weight, Ease of Opening, Blade Material, Overall Quality, Blade Sharpness

Cons: None

Much better than my old one!

Fifty years ago, I purchased a carbon steel Japanese version. At that time, I did not realize it was a copy of this German made classic. Although still serviceable, I thought that I would be better served by a stainless version. I am thrilled at the quality of this product. Most stainless lockblade designs today have beltclips or other accoutrements that make them bulky and defeat the purpose of a convenient carry in an all-purpose knife. If this one is good for another 50 years, I will not be around to get full use of it, but it will be passed on to one of my kids.

Dan
FL

Apr 24, 2025

Pros: Blade Material, Blade Sharpness, Ease of Opening, Handle Feel, Handle Material, Lock Ease of Use, Lock Type, Overall Quality, Pocket Clip, Sheath, Weight

Cons: None

Great Knife

Great german made knife. I have the k55k in Carbon but found it rusted too easily. So I decided to get the stainless version, it's a perfect all around knife. Otter messer is a great brand for classic knives at good prices.

Valky
Augusta, Ks

Jun 11, 2022

Pros: Blade Material

Cons: Weight

old reliable

This is the knife I keep in my shop. I think I paid $20 for it back in the day. It's sharp from the get-go, sturdy as hell and can take about any abuse you can give it. It's a top quality no frills work knife that can handle any task that requires cutting. It's hard to beat Solingen Steel!

Reg R
New Zealand

May 18, 2012

Pros: Weight, Ease of Opening, Handle Material, Blade Material, Overall Quality, Blade Sharpness

Cons: None

A good black cat

Light and good for every-day-carry. Locks well, sharpens well, may take a genuine razor edge. We had these several decades ago in NZ, but I'm not sure whether they locked. We used to call them "Possum skinners". This is a good model. The type of stainless used is easily sharp enough and you don't need the inconvenience of a 'carbon-steel' one.

Greg M
UPM

Oct 14, 2014

Pros: Weight, Ease of Opening, Handle Material, Pocket Clip, Blade Material, Overall Quality

Cons: None

K55 Blackcat

Great knife for our craftsmen to use. Durable yet light weight and small enough to carry comfortably in your pocket.

Valky
KS

Jul 20, 2022

Pros: Handle Material, Blade Material

Cons: None

best for the price

I have had this knife for years on end at my workbench for whatever use it demanded and a SS one next to my recliner in the man cave.. So sharp, so reliable and as sturdy as they come! And the price is way under comparable blades. For the same money you can choose made in China or made in Solingen Germany. I prefer Otter brand!

Bill Conrad
Emmaus, PA

May 26, 2011

Pros: Weight, Ease of Opening, Handle Material, Blade Material, Blade Sharpness

Cons: Handle Feel

nice, slim, carry knife

every day carry knife, easy to open and close.

Nate
MD

Mar 18, 2015

Pros: Weight, Overall Quality, Blade Sharpness

Cons: None

Basic and solid

Different, but great, looking knife with a story. My only ding against it is the uneven paint in the k55k logo on mine. I have the stainless version. Sharpens well. Lock up inspires confidence. Good light use slicer. Would probably filet decently in a pinch, given the long narrow blade.

Stuart H.
Oshawa, Ontario

Aug 31, 2016

Pros: Weight

Cons: None

"Sometimes, Nostalgia Is Best Left In The Past"

I must admit, the thought of owning a knife that was on the verge of celebrating its' sesquicentennial year of production was rather alluring. However, the specimen that I received had been very shoddily assembled. In fact, the bail was even broken at the attachment rivet. There was a time when cutlery made in Solingen, Germany was, well, "the cat's meow". That's not the case here. If it's a nostalgic and handy army knife you're looking for, seek out a Joseph Allen & Sons 2-piece British Army Knife (NSN9757402). You'll be quite pleased with that trip down memory lane!