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

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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’.

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Things I like
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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)

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Knife Review: Extrema Ratio Sethlans

Back when it was launched, I took a ‘first look’ at the Extrema Ratio Sethlans knife. Now, after being able to use the Sethlans for several months I can bring you this much more detailed look at the knife and its comprehensive equipped sheath.
The Sethlans is designed to be used for bushcraft, survival, and as a backup blade, so is also ideally suited for prepping, but I can tell you know, you are definitely going to want to use this knife.

The ‘First Look’ Video:
Taking you back to the initial impressions and overview of the Sethlans.


What’s in the box?:
Extrema Ratio knives always come in a nice robust presentation box.


A good look round the Sethlans Sheath – Things to look out for here are:

A good sheath can make or break a knife, as access to, and ease of carry, affect your experience of using the knife. The Sethlans has one of the most comprehensively equipped and well thought out sheaths of any knife I have used, and there are so many details to show, it is a major part of this review. The following gallery takes you through the construction, assembly methods and components of the sheath, including the sharpening stone pouch and fire-steel that come with the Sethlans.
This sheath can be fully disassembled and reassembled either as a left-handed setup (It comes as a right-handed setup), or stripped down to the very basics. You can run this sheath as just the Kydex sheath with no hanger, or the Kydex sheath with belt hanger/Molle mount. Super flexible design.


The Knife:
This gallery seems rather small after the sheath rundown. The Sethlans is a simple and elegant design that manages to incorporate the distinctive Extrema Ratio finger grip styling and take this feature yet further into the shaping of the actual tang within the grips where the metal is thinned down in the finger grip section of tang to mirror the grip shaping. Very nice touch.


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.


What is it like to use?
Being an Extrema Ratio knife, the Sethlans seems to be both typically characteristic of the brand, yet at the same time completely different and surprising. It also has me in a dilemma about how to set it up thanks to the super flexible sheath design.
If I were packing in a ‘prepping’ style, I would leave the full Sethlans sheath setup with the sharpening stone and fire-steel, as like this you have all the bases covered. However as I am enjoying using this knife, and with the sheath pared down to the minimum, for me it is a much nicer every day carry. In this setup, I remove the pouch with sharpening stone, the fire-steel, and the handle retaining strap. This leaves the knife securely in the Kydex holder on a belt loop hanger.
The knife immediately feels at ease in the hand, comfortable, well balanced and agile. The grip is relatively slim for an Extrema Ratio knife, and this adds to the mobility and control for fine work.
Thanks to the thick full tang, the weight feels like it is in your hand, and the knife will just sit balanced on your first two fingers without trying to fall forwards.


The way the edge sweeps up towards the tip, gives you something similar to a chisel that you can use for nice controlled cuts by pushing down into whatever you are cutting. This same shape also works well as a skinner.
Areas of deep, wide and grippy jimping make for a very stable hold, and there is also the Extrema Ratio distinctive finger groove I have always loved.

Between the thumb jimping and swedge is a section of the blade spine that has been given a nice crisp edge, just right for scraping sparks off the big fire-steel. It does this very nicely indeed…


Fire-steels always make a mess that looks much worse than it is. The Sethlans cleans up perfectly after a fire lighting session, and the photo below, after a clean, left a knife looking as good a new. Use it!

Despite the significantly thick blade tang, the blade itself has a thickness of 3.9mm combined with a depth of 37.5mm, and this makes for a 5 degree primary bevel angle. The figures might be a bit of a yawn, but what it means is a blade that slices really well thanks to the small bevel angle – yet at a maximum thickness at the spine of nearly 4mm, is still a good strong blade without feeling heavy.

Extrema Ratio have put a lot of effort into the complex shaping of the blade, tang and handle fittings, and it shows. These design details make the Sethlans one of those knives you pick up and virtually forget about while using it, as the tool becomes an extension of your hand. You focus on the job, not the tool.

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.

_______________________________________________
What doesn’t work so well for me
_______________________________________________

The Kydex sheath has a bit of side to side play due to the strap layout.
Reconfiguring for left-handed use requires full disassembly of straps and sheath bolts.

_______________________________________________
Things I like
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Excellent balance of the knife.
Comprehensively equipped sheath.
Sheath can be reconfigured for left-handed use.
Modular sheath allows user to choose favourite setup.
Very good handling and grip.
Strong but slicey blade profile.
Easily strikes showers of sparks from a fire-steel.
Compact package.
Secure blade retention, yet easy to remove using thumb pressure.

 
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)