SOG Specialty Knives & Tools was founded in 1986 by designer and toolmaker Spencer Frazer. Named after the elite Vietnam-era Special Forces military group known as the Studies and Observation Group, the company’s first knife was a replica of the original SOG Bowie knife. The company now offers a wide range of edged tools for professional, outdoor and every day use, as well as other gear.

The SOG Pentagon XR™ is a new for 2020, easy-to-carry full-size tactical folder that is optimized for self-defense and combat. The Pentagon XR is designed to offer a more compact folding alternative to SOG’s popular Mini Pentagon fixed-blade back-up dagger, upon which it is based.

Designed specifically for professional users—first responders, law enforcement and military—the SOG XR is the direct result of insight and feedback provided by SOG’s cadre of subject matter experts, according to Jonathan Wegner, Vice President of Brand for SOG.

The Pentagon XR is a robustly built knife that features a 3.6 inch cryogenically heat-treated Carpenter CTS XHP stainless steel (59-60 HRC), wide spear point blade with a matte-black titanium nitride finish. The blade is 0.12-inch thick. The knife has an overall length of 8.38 inches open and 4.77 inches closed. It weighs 4.9 ounces.


G10 handle on SOG Pentagon XR is exceptionally ergonomic and provides excellent grip.


SOG Pentagon XR has a reversible pocket clip for right or left hand tip up carry.


Carpenter CTS XHP stainless steel is a high-carbon, high-chromium powder metallurgy stainless steel. It can be thought of as either a high hardness 440C or a high corrosion resistance D2 tool steel. It is a premium stainless that’s also considered to be one of the “super steels.” It is used in high-end cutlery and applications requiring a high degree of corrosion resistance and wear resistance.

SOG went with CTX XHP for the Pentagon XR since it, according to SOG, “provides” the ideal combination of edge retention and durability for heavy use with minimal maintenance.” CTS XHP offers great edge retention and exceptional corrosion resistance. It is reasonably tough considering its high hardness. It is also harder to sharpen due to its hardness.

The titanium nitride (TiN) coating on the blade reduces friction and provides additional resistance to wear and corrosion. TiN is twice as hard as steel and is exceptionally durable.

The plain edge spear point blade provides a good balance between piercing and slicing ability. It concentrates 100% of the thrust force along the exact center-line of the knife. It combines the sharp point of a dagger with the strength of a drop point blade, while retaining some of the belly of the latter for cutting and slicing.


Pentagon XR leverages feedback from professionals with a focus on defense and combat.


The blade features a deep fuller on both sides and has a small sharpened back edge for enhanced penetration and delicate work. Technically, the sharpened back edge, albeit small, puts the Pentagon XR in the double-edge knife category from a legal perspective. The Pentagon XR came hair shaving sharp out of the box.

The Pentagon XR is designed for single-handed ambidextrous use. All functions are accessible with either hand. It offers you three modes of ambidextrous opening to suit your preference — thumb stud, flipper and inertia opening. It features a ball-bearing pivot system to reduce friction and allow for smooth and rapid deployment.

The patented XR locking mechanism is strong and completely ambidextrous. It allows you to close the knife without ever placing your fingers in the path of the blade. It also allows for easy inertia opening by simply holding back the lock and flicking out the blade. Lock up is rock solid with no blade play.

The XR lock works using a small hardened steel spring-loaded transverse round bar with sliding buttons that moves in a machined groove in the liners and engages a notch in the tang of the blade when the knife is opened. The bar is held in place by the hardened stainless steel liners. The stop pin positions the blade for additional strength and reliability. The XR lock mechanism also serves as a detent to hold the blade in the closed position. According to SOG, the XR lock is able to withstand a whopping 1,500 pounds of force. The XR lock is self adjusting for wear.


SOG Pentagon XR spear point blade is ideal for self-defense. It is made of CTS XHP stainless steel for corrosion resistance and edge retention.


Ambidextrous XR lock on SOG Pentagon XR is capable of withstanding 1,500 lbs of force. Knife offers three modes of opening—flipper, ambidextrous thumb studs and inertia.


Stainless steel liners are nestled in recesses machined into the knife’s scales to reduce handle thickness and provide support for the XR lock. The liners are skeletonized for weight reduction.

The handle is of partially open back design and has “Ultra Grip” G10 scales with radiused edges. The Ultra Grip texturing provides a very “grippy” slip-resistant grip without being so aggressive as to be hard on pockets. It is available with either black (Blackout) or OD Green G10 scales. I was provided with the Blackout model.

The Pentagon XR feels great in the hand. It is well balanced. The handle has a neutral shape except for a large finger choil. The choil serves to index the knife and provide additional security in the hand. There is jimping in all the right places. The flipper also serves as a handguard to protect your hand.

The Pentagon XR has a black ambidextrous (two position) low-profile heat treated stainless steel wire flat pocket/belt clip for tip-up carry.
The clip and the scales are attached with stainless steel Torx socket screws.

The clip doesn’t create any hotspots when the knife is gripped. In fact, I don’t even notice it is there. The design of the clip allows for easy in and out of pockets, even those with a thick pocket edge, yet is very secure. Th butt of the handle is roughly 0.5-inch above the top of the clip, making the knife easy to grab in high stress situations.

Fit and finsh on the Pentagon XR are excellent. The Pentagon XR has a MSRP of $174.95. If you are in the market for a great tactical folder, definitely check out the new SOG Pentagon XR.

SOG Specialty Knives & Tools