In close quarters fighting, there is no more deadly weapon than the knife…” W. E. Fairbairn. Get Tough (1942).

SOG Specialty Knives and Tools (SOG) is no newcomer to the tactical knife game. SOG was founded in 1986 by designer and toolmaker Spencer Frazer. Named after the elite Vietnam-era multiservice special operations unit. known as the Military Assistance Command, Vietnam — Studies and Observation Group (MACV-SOG), the company’s first knife was a replica of the original MACV-SOG Counter Insurgency Support Office (CISO) issue Bowie knife. SOG was acquired by GSM Outdoors in December 2021.

The SOG Pentagon fixed blade knife has also been a fixture of SOG knives for decades. The Pentagon fixed blade has recently gotten a revamp with the new Pentagon FX series. The Pentagon FX is available in two sizes to meet the needs of distinct missions. The SOG Pentagon FX Covert is the shorter version of the new Pentagon fixed blades. It combines modern design and materials with classic dagger styling in a compact package.

The Pentagon FX Covert is a small format fixed blade knife designed for discreet concealed carry.

Designed for ease of concealment, the SOG Pentagon FX Covert features a 3.41″ flat-ground double-edge spear-point full-tang blade with a 3.25″ straight cutting edge. The blade is made of CRYO CPM® S35VN™ stainless steel with a hard, wear-resistant stealthy matte black titanium nitride PVD (physical vapor deposition) coating. Titanium nitride PVD is a functional coating that protects the blade and provides lubricity. The blade has a fuller (often erroneously referred to as a “blood groove”) on each side for added aesthetic appeal. The blade is 0.88″ wide and 0.18″ thick. The Pentagon FX Covert has an overall length of 7.52″. Weight is 3.9 oz.

CPM S35VN a top-grade martensitic stainless steel that’s often referred to as a “super steel.”. It has become one of most popular stainless steels with knife makers. Made in the USA by by Crucible Industries, it’s a tougher version of the popular CPM S30V, due to the addition of 0.5% niobium. The addition of niobium makes CPM S35VN about 15% to 20% tougher than CPM S30V. CPM S35VN has has 14% chromium to maximize corrosion resistance without giving up too much toughness.

The Pentagon FX Covert has a 3.41” CRYO S35VN full-tang double-edge spear-point blade with matte black titanium nitride PVD coating.

CPM S35VN offers what many consider the best combination of toughness, wear resistance, stain and corrosion resistance. It offers better resistance to chipping than CPM-S30V, while maintaining ease of sharpening relative to its wear resistance. I say “relative to edge retention” since CPM S35VN can take a little longer to sharpen.

The steel is important, but it’s only part of the performance equation. The heat treatment is as important as the steel, if not more so. SOG utilizes a unique computer-controlled cryogenic heat treatment process that maximizes the performance of the blade. The blade on the Pentagon FX Covert has a hardness of 59-61 RC. This is considered the sweet spot for CPM S35VN.

The blade on the Pentagon FX Covert came with what I would call a working edge. Not razor sharp, but definitely more than up to the tasks it would be expected to perform. It holds an edge well, as would be expected given the steel and heat treatment. The CPM S35VN blade Is capable of taking a keen edge.

The G10 handle scales on the Pentagon FX Covert are textured for optimal grip. The G10 scales feature a single-fastener slip-on / slip-off design for maximum mission flexibility.

The handle on the Pentagon FX Covert is 4.125″ long. The handle is 1.00″ wide and 0.50″ thick. The handle has removable single-fastener slip-on / slip-off G10 scales. The that can be easily removed for a slimmer profile, although the handle is already quite slim with the scales attached. The two-part single fastener is on the butt of the handle and also serves as a lanyard hole. SOG has an excellent video on removing and reinstalling the scales.

As many readers know, G10 is a composite of glass fiber and epoxy resin. It is very durable, resistant to moisture, chemicals, and temperature changes. G10 is relatively heavy compared to other materials, which can affect the balance and feel of the knife, although this is not an issue on the SOG Pentagon FX Covert. The knife is perfectly balanced.

The Pentagon FX Covert has an ergonomic design. The knife is very well balanced.

The handle on the Pentagon FX Covert features ample contouring, jimping on the tang in all the right places and texturing that provide a comfortable and solid non-slip grip. The machined micro-texture surface on the G10 scales provides the right amount of grip in the right places without being so aggressive as to abrade your hand or wear out your clothes. There are also thumb scallops on each side that provide additional purchase when thrusting using a forward grip. The symmetrical handle design allows for use with any grip or blade orientation and maximum blade control. The handle has two opposing finger grooves that serve as a dual guard. The handle is optimized for comfortable concealment. I have average size hands. I can just get a four fingered grip on the handle.

The Pentagon FX Covert comes with an ambidextrous friction-fit glass-reinforced nylon (GRN) sheath featuring SOG’s new Universal Mounting System (UMS). The UMS with be the basis for all SOG sheaths going forward, It allows users to personalize how they carry the knife with interchangeable mounting options. The Pentagon FX Covert sheath is low profile and minimalist for discreet carry. The sheath is quite secure and rattle free. The knife isn’t going to come out unless you intentionally draw it. Although the sheath on full-size Pentagon FX features tool-less retention adjustment, the retention level of the sheath on the Pentagon FX Covert is not adjustable.

The Pentagon FX Covert has low profile, minimalist sheath. The sheath is made of GRN.

The Pentagon FX Covert comes out of the box with a SOG UMS metal belt clip installed. The clip can easily be removed or adjusted using a T8 Torx driver. The clip fits belts up to 2.25″ wide and may be mounted for vertical or horizontal carry. The clip is very secure on the belt. The sheath is also compatible with SOG’s other UMS accessories. The sheath is also compatible with other popular aftermarket mounting accessories. The sheath can be used without any hardware through a PALS webbing channel or by mounting adhesive Velcro® hook for attachment to loop panels.

The Pentagon FX Covert sheath features SOG’s Universal Mounting System (UMS) for flexible mission setup. It comes with metal UMS belt clip.

The Pentagon FX Covert is available in two models: Pentagon FX Covert – Flat Dark Earth (FDE) and Pentagon FX Covert – Blackout. The FDE model has FDE scales and a FDE sheath. The Blackout model has black scales and a black sheath. Both models have black blades and hardware. I was provided with the Pentagon FX Covert – FDE model.

The Pentagon FX Covert has been very well thought out. It is extremely rugged and very ergonomic. It is perfectly suited as an EDC defensive knife. Fit and finish are top notch, as are the materials. It is made in Taiwan and comes with a limited lifetime warranty. MSRP is $189.95 USD.


SOG Specialty Knives & Tools (SOG)

GSM Outdoors

SOG Pentagon FX Covert

Brand: SOG
Product Type: Fixed Blade Knife
Model: Pentagon FX Covert
Overall Length: 7.52″
Blade Length: 3.41″
Cutting Edge: 3.25″
Blade Width: 0.88″
Blade Thickness: 0.18″
Blade Material: CPM S35VN
Blade Hardness: RC 59-61
Blade Style: Spear Point / Dagger
Blade Grind: Flat
Finish: Black Titanium Nitride PVD
Edge Type: Straight Double-Edge
Handle Length: 4.125″
Handle Width: 1.00″
Handle Thickness: 0.50″
Handle Material: G-10
Color: FDE or Black
Weight: 3.9 oz.
User: Ambidextrous
Sheath: GRN
Mount: UMS Belt Clip
Country of Origin: Taiwan
Best Use: Tactical, EDC
Warranty: Limited Lifetime
MSRP: $189.95 USD

Material Disclosure

I received this product as a courtesy from the manufacturer so I could test it and give my honest feedback. I am not bound by any written, verbal or implied contract to give this product a good review. All opinions are my own and are based off my personal experience with the product.

*The views and opinions expressed on this website are solely those of the original authors and contributors. These views and opinions do not necessarily represent those of Spotter Up Magazine, the administrative staff, and/or any/all contributors to this site.

By Eugene Nielsen

Eugene Nielsen provides intelligence and security consulting services. He has a bachelor's degree in political science from the University of California. His byline has appeared in numerous national and international journals and magazines.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.