Reviews and Ratings for Spyderco Police 4 Lightweight Folding Knife 4.38" K390 Satin Plain Blade, Blue FRN Handles - C07FP4K390

Spyderco Police 4 Lightweight Folding Knife 4.38" K390 Satin Plain Blade, Blue FRN Handlesrated 4.75 stars out of 5 (8 reviews)
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Spyderco Police 4 Lightweight Folding Knife 4.38 inch K390 Satin Plain Blade, Blue FRN Handles

 

Price: $198.00

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Spyderco Police 4 Lightweight Folding Knife 4.38" K390 Satin Plain Blade, Blue FRN Handles
rated 5 stars out of 5
Big-Ev
CALIFORNIA
Jan 23, 2026
Pros: Blade Material, Blade Sharpness, Ease of Opening, Handle Feel, Handle Material, Lock Ease of Use, Lock Type, Overall Quality, Pocket Clip, Weight
Cons: None

Great

I use this knife at work. Cutting tape, breaking down boxes etc. It is so slim in the pocket I can barely tell it's there. I like how the metal is wearing in with patina.

Keep out of the way of corrosive substance. I spilled some hot sauce on it and it got a little blemish. I quickly wiped it off and it didn't affect it other than a dark spot. But that just adds character to it in my opinion
Spyderco Police 4 Lightweight Folding Knife 4.38" K390 Satin Plain Blade, Blue FRN Handles
rated 5 stars out of 5
Bigp7
Connecticut
Mar 17, 2021
Pros: Weight, Ease of Opening, Handle Material, Blade Material, Overall Quality, Blade Sharpness
Cons: None

Great large Spyderco Police 4 with K390 steel!

Wonderful knife with great steel just oil it from time to time.
Spyderco Police 4 Lightweight Folding Knife 4.38" K390 Satin Plain Blade, Blue FRN Handles
rated 5 stars out of 5
Yt
New York
Mar 08, 2021
Pros: Weight, Blade Material, Overall Quality, Blade Sharpness
Cons: Handle Feel, Handle Material, Pocket Clip

More solid-feeling in hand than expected

Firstly, I thought the FRN-handled knife would feel flimsier and more lightweight in hand than the G10-handled version; However, the opposite is true, and this knife feels solid despite its slim and long blade and handle. There are hefty full-length steel liners "concealed" by about 1/8" of FRN, with some half-hearted attempt to lighten them up by opening some circular holes, but the knife still feels hefty and substantial - this is not a Pacific Salt2 or a Manix2 lightweight by any means! The blade In my example is well-centered (- it is well known as possibly problematic issue with some models), and the lockup is as solid as a bank vault door. Trying to close the blade with one hand is just not gonna happen. I got the knife because of its blade - it is an awesome blade as it is long and thin, which makes it a great "slicer"! The K390 steel is just a cherry on top. Lastly, this is one matter-of-fact knife:- Riveted handle means no customizing, so beautification and customization connoisseurs need not apply. The backlock means this is not a fidget-friendly knife either, so those with nervous ticks needing to have their fingers occupied also need not apply. As to what it will do - everything, except substituting for a fidget spinner and customization laboratory. Good knife! Hope this helps. Cheers!
Spyderco Police 4 Lightweight Folding Knife 4.38" K390 Satin Plain Blade, Blue FRN Handles
rated 5 stars out of 5
Bradley
Midwest
Mar 18, 2021
Pros: Ease of Opening, Overall Quality, Blade Sharpness
Cons: None

Huge folder greatness.

This knife is crazy. Biggest folder I own. Super sharp, good feel in the hand, fits in the pocket pretty well for its size, and steel liners which I always prefer. This is no really good reason to buy a folder this big, unless you want to and I wanted to buy this beast. Price is a little on the high end, but did not stop me from buying.
Spyderco Police 4 Lightweight Folding Knife 4.38" K390 Satin Plain Blade, Blue FRN Handles
rated 5 stars out of 5
Michael
Lebanon, Mo
Jul 14, 2021
Pros: Weight, Handle Material, Pocket Clip, Blade Material, Overall Quality
Cons: Lock Ease of Use

My Absolute Favorite Hard Use Pocket Knife

Is it pretty? That depends on whether you think function is beautiful. I do and I think its gorgeous. Ya, ok, it has FRN handle material. Is G-10 better? Not for all day use and carry on the job in my opinion. FRN makes this knife lightweight and un-noticeable. This knife is about the blade steel and geometry. Period. The factory edge is useable immediately. K-390 is a "super-steel" for a reason. Edge retention is off the hook. The toughness is perfect for slicing. Do you pry with your knife? Get CPM 3V. If you want epic edge retention in a working knife get K-390. I sharpen my knives to 650 grit on one side of the bevel and 4000 grit on the other side, followed by a good stropping to 1 micron. This gives the edge a nano-serration and a very long lasting, crisp/aggressive edge for slicing. Its hair popping boys and girls. Equal to any razor blade. Say good buy to your utility knife with replaceable blades. At 4.38", the length is perfect for cutting insulation, pex tubing, flex duct and etc. Yet, it's not too long where its not comfortable to use for stripping wire, opening packages, breaking down cardboard boxes and etc. Ok, sure, the steel will stain and rust like a utility knife blade. Who cares? Just keep some oil on it. Any oil that you normally carry with you will do. This knife is a working mans dream.
Spyderco Police 4 Lightweight Folding Knife 4.38" K390 Satin Plain Blade, Blue FRN Handles
rated 5 stars out of 5
Ryan H
Missouri
Mar 17, 2021
Pros: Weight, Ease of Opening, Handle Material, Pocket Clip, Blade Material, Overall Quality, Blade Sharpness
Cons: None

Game changer!

I love the lightweight line and K390 is from my experience, one of the best steels I own. Not to mention that it looks awesome once it's patinaed. I have always leaned toward the Endura, carrying it the most out of my collection because it's size allows me to do a large variety of task. Now Spyderco outdid themselves by making the Police a lightweight with a super steel! This knife is more than impressive to hold and using it in the kitchen is like using a chef knife. I freaking love this thing and because I'm a weirdo, I am defiantly getting a second one
Spyderco Police 4 Lightweight Folding Knife 4.38" K390 Satin Plain Blade, Blue FRN Handles
rated 5 stars out of 5
Not As Big Tex
North Texas
Jan 04, 2026
Pros: Blade Material, Blade Sharpness, Ease of Opening, Handle Feel, Handle Material, Lock Ease of Use, Lock Type, Overall Quality, Weight
Cons: Pocket Clip

It's big

The Spyderco Police 4 in K390 is big. It makes me feel like a real man when I pull it out and other, lesser men, with their cute and petite folders, comment on how large it is. They say it's so big, it must be unwieldy, to which I say nay. Tis not. It is quite the satisfying size! Jokes asides, it's big. Don't get it unless you have other 3.5inch+ knives and want more. The action is damn smooth, and very nice for a lockback which all have some resistance. Feels good in the hand, though the long blade won't let you get too comfortable or relaxed. It slips into a pocket very well due to its thinness and sleek closed-shape. It's shocking how quickly it becomes unnoticeable in the pocket. The bi-directional texture on the handle feels less abrasive than my Endura while still being grippy. The blade steel is tough, but mine did slightly rust fast. Some condensation or sweat built up in the pocket and caused a slight patina. In hindsight, I would have gone with the VG-10 model because the shape is great for light kitchen tasks. It's not great for general EDC-use outside the kitchen. Honestly, I still prefer the Resilience for a big EDC knife. But the Police 4 was a feel-good knife for me, and I really like carrying around a 'pocket sword'.
Spyderco Police 4 Lightweight Folding Knife 4.38" K390 Satin Plain Blade, Blue FRN Handles
rated 3 stars out of 5
Hawkbill
Baltimore, Maryland, USA
Apr 01, 2021
Pros: Weight, Ease of Opening, Blade Material, Blade Sharpness
Cons: Lock Ease of Use, Lock Type

Great K390 blade, but P4 has a lock rock issue

Great K390 steel, very sharp. Keep in mind K390 requires frequent maintenance to prevent corrosion. However, all Police 4 FFG I have owned (both the VG10 and K390) suffer from a lock rock issue. Vertical play isn't too bad, but it distracts from the quality of the knife. Other Seki-made Spydies I have do not have this issue. For example, all my Matriarch 2 are solid, no play whatsoever. The P3 stainless didn't have any play either.
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