Columbia River CRKT M21-14 Carson M21 Combo Edge Knife
 

Probably belongs in the survival section really, but anyway...

Just bought a:

Columbia River CRKT M21-14 Carson M21 (Folder) Combo Edge Knife just like this one:

http://i9.ebayimg.com/07/i/001/26/17/d3d2_35.JPG

http://i.ebayimg.com/12/!BZ5iF2w!2k~...,IEDyQ~~_3.JPG


Try and imagine the above in stainless blade form like the top image.




I was weighing it up against a Carson M16 like this one (Sold as a police edition and various other editions, only in standard black). They were both the same price, and I figured the M21-14 being a bit bigger would have more flexibility in use. The M16 knife seemed very nice too though, and I can see why they would be so popular.

Note that these are not to scale, the M21 is fairly bigger than the knife below:

http://www.1sks.com/store/media/crkt...r-m16-13zm.jpg


So far, initial impressions are very good. I love the build quality, it opens and closes easily, and has a good dual open-locking mechanism. Blade sharpness out of the box is very good, and will slice a piece of paper easily. Not ridiculously sharp, but sharpened for it's purpose.

Here is the commercial blurb on the knife:


Columbia River CRKT M21-14 Carson M21 Combo Edge Knife

When a series like Kit Carson's aluminum handled line has been so successful, it is bound to spark calls for variations. In this case, the request was for a spear point blade similar to Kit's M18 design. As soon as they saw the first sketches, Columbia River knew they should offer it in two sizes similar to the "Little Bulldog" and "Big Dog".
The new swedged and recurved blade is ground to a spear point shape, using premium AUS-8 stainless steel in non-reflective frost finish to offer superior edge retention. The grind incorporates a false top edge and deep belly, yet retains a full width central spine for most of its width for maximum strength. We offer both Razor-sharp and Combined Razor-Sharp and Triple-Point� Serrated edge grinds.
Teflon� bearings at the blade pivot assure velvety smooth one hand opening and closing, using Kit Carson's trademark dual checkered thumb studs which also act as a blade stop.
The M21 feature the very popular "Carson Flipper" blade extension, which aids opening and acts as an additional blade guard.

Features

Blade Length: 3.937"
Overall Length: 9.25"
Blade Material: AUS-8 Stainless Steel
Weight: 4.2oz.





We get pretty badly ripped off here on knives, so I won't say the price was excellent, but I see in the U.S. you can pick these up for $58-78 USD.

Re: Columbia River CRKT M21-14 Carson M21 Combo Edge Knife
 

I have several I like the knife but what ever they make them out of is tough to sharpen, you will never get the factory edge back once you lose it.

Re: Columbia River CRKT M21-14 Carson M21 Combo Edge Knife
 

The CRKT knives are of a decent quality with a mid-range steel, personally I like AUS-8...it is an older steel but one that sharpens easily and holds an edge well. I have several CRKT blades and they are about what you would expect for the money.

Re: Columbia River CRKT M21-14 Carson M21 Combo Edge Knife
 

What do you use to sharpen them back up?

Just a stone with some water or oil? Or a specific sharpening device.

AUS-8 is a bit more prone to corrosion I believe. They do tell you how to take care of the things and I do oil knives and store them with dessicant as this helps protect them a lot, particularly the
dive knife that has seen some duty.

Re: Columbia River CRKT M21-14 Carson M21 Combo Edge Knife
 

Ive had several CKRT knives. Wont buy another. The steel not to my liking. I should say however, I have a small ckrt that seems to hold an edge ok, but all the rest, expecially the larger ones did not. I either stick to cold steel, buck or spyderco. However, It all comes down to the steel being used. Do a little research on the types of steel used in knives. It really does make a difference. Absolutely stay away from stuff like 440A. The designation "8Cr13MoV" is a good compromise in terms of price and performance. You can move up from there into S30V or D2 steels. From my experience, the Aus8 steels are similar in performance to the 440 series steels.

Re: Columbia River CRKT M21-14 Carson M21 Combo Edge Knife
 

I think the AUS-8 is basically equivalent to a 440C, which is a high carbon steel+chromium. Many different knive steels are used, and it totally depends on what properties the knife is designed for.

eg. Taking/retaining an edge, flexibility, strength, corrosion-resistance. It's all a trade-off.



http://www.interlloy.com.au/data_she...teel/440c.html



440C is a high carbon straight chromium high hardenability martensitic stainless steel, generally supplied in the annealed condition with a maximum Brinell hardness of 269 (Rc29) or annealed and cold drawn with a maximum Brinell hardness of 285 (Rc31).
Characterised by good corrosion resistance in mild domestic and industrial environments, including fresh water, organic materials, mild acids, various petroleum products, coupled with extreme high strength, hardness and wear resistance when in the hardened and tempered condition.
440C due to its excellent hardenability is capable of being through hardened up to Rc60 depending upon carbon content and section size. Small sections can be air cooled and quite large sections oil quenched for maximum through hardness.
Used for parts requiring a combination of excellent wear resistance, plus reasonable corrosion resistance. Typical applications are: Ball Bearings and Races, Bushings, Cutlery, Chisels, Knife Blades, Pump Parts, Surgical Instruments, Valve Seats etc.
Material magnetic in all conditions.