Knife Review: Extrema Ratio T4000 C

Included in this review of the Extrema Ratio T4000 C, a compact classic Tanto with Extrema Ratio’s tactical sheath and handle, are a video with an overview and detailed measurements, galleries of the packaging, sheath, and knife, plus insights into how it is to use.

Let’s take a closer look.

The video tour of the T4000 C:
In case you haven’t seen the video overview and vital statistics of the T4000 C on Tactical Review’s youtube channel, here it is. This video covers a quick tour of the knife and sheath and a detailed technical measurements section.

A few more details:

What’s in the box?:
For the T4000 C, it ‘just fits’ into the box. The usual Extrema Ratio high quality two-part box is used.

A good look round the T4000 C’s Sheath – Things to look out for here are:
Even though ‘Compact’ the sheath manages to fit in a lot of features and details. Solidly constructed and made to fit the compact knife perfectly. On the back is a set of PALS/MOLLE webbing and strap, with the front also having webbing for mounting a small pouch or other item. A gap in the welt at the base of the sheath allows for free flowing drainage. To comfortably accommodate the thick blade stock the welt is similarly sized.
A strong double press-stud retaining strap wraps the handle and keeps the knife securely in place. you can adjust the position of the retaining strap as it is held in place with a Velcro adjusting system. There is an anti-catch smooth plastic insert backing the sheath to prevent wear and damage to the back of the sheath when sheathing the knife.
With there not being a specific belt loop, using the MOLLE strap, you can make your own belt loop to fit the size of the belt.

The T4000 C knife itself:
From the first view of the satin blade emerging you get drawn into admiring the knife. The beautifully executed fuller on each side of the blade enhances the lines. Extrema Ratio’s distinctive grip design provides an index finger groove to give a strong grip. A single bolt holds the rubber grip in place on the full tang, that extends through to a striker and lanyard hole. Sharpening choils – what is your take? – well the T4000 C does not have one, so the sharp edge stops just short of the plunge line. Also note a front lanyard hole, allowing you to fit a cord to both the front or rear of the handle.
Being the compact model, the handle length sits just within the hand (I take XL size gloves).

The Blade and Handle – Detailed Measurements:
For full details of the tests and measurements carried out and an explanation of the results, see the page – Knife Technical Testing – How It’s Done.

There is a lot to take in here. These measurements are shown in the video.

What is it like to use?

It’s a tanto – nice – I always like a tanto. There is a practicality of having an almost chisel-like tip and what I refer to as the secondary point (where the tip and main edge meet) for various cuts instead of using the actual tip of the knife.
The elegant lines are simply a pleasure to look at as well as to use, and being the compact knife class from Extrema Ratio this is a really useful day to day blade. Something you are more likely to pick up and use, as it is very practical.

I knew after measuring the factor edge I would want to re-profile the edge bevel, 25DPS is too wide/heavy for a small knife, even 20DPS would be more than I want. But before doing this, with the sharpness measuring a respectable 281 BESS average I wanted to see how it fared. It would not shave arm hair with this edge, however…

Factory edge put to some minor fire prep tasks. The wood here is fully seasoned so much harder than any green wood. Kindling and feather sticks, perfectly good with these little pieces of wood, using the edge out of the box.

After a bit of use, it was time to change the edge bevel to 17DPS and bring that cutting edge a bit closer to the plunge line. As always, putting your own edge on a knife makes all the difference, and now it sings along shaving and slicing ferociously.

Extrema Ratio are good at Tantos, and this is one of their best. The thinned down blade thickness with full flat grind give it great slicing power, yet the blade still starts at 4.1mm at the spine, so is plenty strong for heavy use. Go back and look at the blade in the video as the light plays off it and you really appreciate the qualities of the T4000 C.

Review Summary

The views expressed in this summary table are from the point of view of the reviewer’s personal use. I am not a member of the armed forces and cannot comment on its use beyond a cutting tool or field/hunting knife.

Something that might be a ‘pro’ for one user can be a ‘con’ for another, so the comments are categorised based on my requirements. You should consider all points and if they could be beneficial to you.

I’m trying something slightly different and starting with what doesn’t work so well, so I can finish on a more positive note

What doesn’t work so well for me

No sharpening choil – personal preference.
Retaining strap is a bit bulky for a compact knife.
Factory edge usable but a bit ‘heavy’.

Things I like

Build quality and finish.
Practical well designed sheath.
‘Handy’ size being a ‘C’ Compact model.
Very comfortable grip.
Front and rear lanyard points.
Elegant blade profile with fullers.
Reliable steel choice.

Discussing the Review:
The ideal place to discuss this review is on the Tactical Reviews Facebook Page
Please visit there and start/join the conversation.

As well as the Tactical Reviews Facebook Page, please consider visiting one of the following to start/join in any discussion.

BladeForums – Knife Reviews (US based Forum for Knife Discussion)

CandlePowerForums – Knife Reviews Section (Largest and Friendliest Flashlight Community Forum)