Extrema Ratio T4000C Review
Last year I reviewed the Extrema Ratio Shrapnel and that 4” bladed knife has become one of my favorites for everyday carry. The Shrapnel has a new brother; the new T4000 C Tanto bladed knife is now part of Extrema’s Back-Up Knife line. As a fan of tanto blades for defensive use and was excited to see the T4000 C introduced with a fat high aspect ratio tanto point angle. From a comparison perspective, the Shrapnel delivers a modified 4.3” drop point blade and the T4000 C delivers esthetically the same knife with a marginally shorter 4.1” Tanto blade.
Extrema Ratio not only makes beefy well designed knives, but also adds features and style not found on other knives which make them easy to use and and delivers a lot of pride of ownership. A bit futuresk, yes, however once these unique handles and knives are in hand, you really appreciate the out of the box thinking of the Extrema Ratio design team. The focus of the Extrema Ratio T4000 C is designed with the focus as a pure defensive backup knife. 
The T4000 C features a cordura sheath versus the multi-mount kydex/polymer sheath for the Shrapnel. The T4000C is compact but not particularly slim. From a concealment perspective it can be difficult to conceal without a dedicated concealment holster. I formed a custom deep concealment carbon fiber kydex appendix sheath which does allow me to conceal the knife. The concealment challenge is the rather large but extremely comfortable handle.
Included with the Extrema Ratio T4000C is a cordura sheath which I found particularly useless for the intent of the knife with the primary limitation being speed of access. The very well thought out hard plastic click-in and click-out Extrema retention sheath better from the other Back-up Knife models is just a better sheath system. At this point I carry the T4000 C in my custom Kydex sheath, so it really is not an ongoing issue for me.
The Extrema Ratio T4000 C features the same Fornprene handle with hardened glass break tang with lanyard hole as the rest of the Extrema fixed blade line. The edge holds extremely well thanks to the N690 cobalt steel. As an EDC knife, this would not be the blade or blade shape I would reach for first for utility tasks or bushcraft. The Tanto blades do an excellent job at excelling at penetrating jabs and slashes, however the shape is less versatile for than a typical drop point blade. Conversely I would rather have a historically proven tanto blade shape than a drop point for a defensive knife that bites and cuts deep.
The T4000 C is not a slim, tiny, and light knife as you see with the BlackHawk/MOD Razorback, but a heavy duty beast of a blade featuring hard use full tang knife design with a full sized handle. This focuses the knife squarely as a defensive knife. The blade contours are consistent and edge grind is perfect with very minor casting seams on the Forprene handle. The Austrian N690 steel is a cobalt based stainless steel similar in performance to the expensive VG-10. Notably the blade is wicked crazy sharp.
FINAL THOUGHTS
This is the top and of production tactical knife making. To date I have tested a number of knives from Extrema Ratio and although I am a very picky guy when it comes to blades, they have continued to impress with every knife. If the Extrema Ratio T4000 C had a slimmer overall handle profile for to allow for more discreet concealed carry it would be “the” perfect knife.
After a few months carrying T4000 and I did round off the pommel and of the handle to make the knife conceal a little better. Sure Extrema Ratio knives are expensive, however the knife is the most essential and basic of survival gear and I believe you should always buy the best knife available when your life may depend on it.
SHRAPNEL SPECS
Weight g.:196.0
Weight oz.:6.9
Blade Length (mm):104
Blade Length (in):4.1
Total Length (mm):208
Total Length (in):8.2
Blade Thickness (mm):4.0
Blade Thickness (in):0.16
Blade Material:BöHLER N690 STEEL (58HRC)
Blade Finishing:MIL-C-13924 BURNISHING
Main Grid:FLAT
Handle Material:FORPRENE
STREET:$208 (XTREME KNIVES)
SOURCES
Extrema Ratio Knives
Xtreme Knives