Cold Steel Spartan

[Mag]

I got a Spartan for christmas, and was really keen on it. I've used it once to slice open a plastic bag of marinaded ribs. Wiped it dry, and put it away.

A couple of days later, I opened it...just to look (you know how it is lol) and noticed little spots all over the blade. it looked like rust spots.

I contacted the shop that I bought it from (yeah I know, not immediately, but it has a year guarantee after all) and they got back to me today.

The guy explained that having those spots, proves the high carbon content of the steel, so its a good thing. Will not affect the blade at all, and I could bring it in and they would polish it for me. He informed me (nicely) that if I knew steel, I would have washed it off and oiled it.

Here's the part that irks me a little. I was under the impression that this was a utility blade that could be used for anything, and now I find out its going to be a bit of a delicate wall flower.

Could someone steer me in the right direction. Is what I've been told true? should I just get them to polish the blade and then oil it and not use it?

Advice will be greatly appreciated.

[Corné]

Dude...I just got one this weekend for a bargain due to the same reason and I am not complaining. Cold Steel makes use of steel with high Carbon content. This offers a lot of advantages and one disadvantage...rust. You do not need to treat it "dilicately" but do need to take a bit of extra care like wiping it every now and then with a oily cloth especially after washing. It does not need to be dripping with oil and a wipe with a oily rage followed with a wipe with a dry rag should do the trick. Go and have a look at some of the Cold Steel knifes on display at Sharp Edge and you will see some have a visual oily coating on the cutting edge to prevent rust. These spots that you see will not do anything to the ability of the blade and if it bothers you..have it polished.

Enjoy.

[Mag]

Tx Boet
Appreciate the advice. Just thought I had bought a dud. None of my other knives have got spots like that, so thanks for clearing it up.

[Corné]

No problem. I am considering changing mine from Spartan to Spotty....but it will still cut the crap out of whatever it encounters!

[Mag]

it is damn sharp, and just once, I want to say: Hey thats not a knife....THIS is a knife lmao

[Samurai Stu]

Hi Mag,

I encounter this problem frequently as I make knives from carbon steel. Whenever I sell a knife to a customer i stress that the blade is not stainless and will rust if not cared for properly. Having said that there are great advantages to carbon steel. Most stainless steels have high chromium which is what gives it the stainless quality. This however also creates a blade that can at times bee too brittle if not heat treated properly. These blades are also sometimes difficult to sharpen if you lack experience.

Carbon steel blades are far more forgiving when it comes to structural strength from the hardening process. Many of CS blades are made from 1050 carbon steel which is a medium range carbon rating but provides greater strength and flexibility. Strength must not be confused with hardness. A delicate balance between the two is what makes a great knife.

As a forger of knives I offer one extra advantage over commercial blades. This is the method of selective hardening. Using carbon steels enables me to create a knife with varying degrees of hardness throughout a single blade. An edge quench (the technique that hardens the steel) hardens onlt one third of the edge while leaving the back of the knife softer and more flexible. This softer back supports the hard edge. I then selectively temper (method of de stressing the steel providing flexibility) the blade so that the tip is slightly softer than the edge but the tang is slightly harder than the back of the blade. These four different hardnesses now provide an blade that still retains a sharp edge but has great flexibility for more stressful applications.

With regards to the effect of rust on your blade. There is a Bladesmith's expression - Only fire can give steel its character and only fire can take it away.

Basically if you buried your blade in the ground for a hundred years and dug it up again it would be covered in a thick layer of rust. But clean the rust off and sharpen it and it will take an edge as sharp as the day it was made.

[marthinus]

The cold steel spartan uses AUS 8A stainless steel (http://www.coldsteel.com/spfko.html).

Here is a chart comparing 440C, AUS 8A and a high carbon steel 1095 (used for rail road tracks)

http://zknives.com/knives/steels/ste...74%2C420%2C360

Generated at: http://zknives.com/knives/steels/ste...74%2C420%2C360

Now, if you have a look the carbon content is lower then 440C or 1095, but the big difference is the chrome content, the less carbon and more chrome, the more stain resistant (in short, it is much more difficult then this). 1095 will rust due to the non excistent chrome, carbon is important in a steel. Why? well:

It is the most important hardening element. Increases the tensile strength and edge retention however, improves resistance to wear and abrasion. added in isolation, decreases toughness. Usually one would want knife-grade steel to have > 0.50% carbon, which makes it "high-carbon" steel. Low Carbon steels have up to 0.03% C, and there are mild steels with 0.03% or similar, obviously those aren't suited for knife blades.

AUS 8A is not classified as a HIGH CARBON steel and with the amount of chrome in the steel should not easily rust, it also does not rust easy and I have used mine in salt water environments for years (even steels with higher carbon content but requires more maintenance such as D2 tool steel and 1095, 1055). The guy that told you it proves it is high carbon does not know what he is talking about IMO. There are hundreds of steels out there using higher carbon content.

AUS 8A is a good "STAIN LESS" then carbon steel, but it will still stain if left unattended. "stainless" has become a pain in the but for many people thinking...ooo the knife says stainless....therefore it will never rust....this is false.

In short, if you ever use a knife and then store it, give it a rub down with a cloth that has some Q20 sprayed on it. The moisture in the air can cause rust.

[Mag]

Wow, thanks guys. Really appreciate the feedback.

[Corné]

Stainless = Stain Less and not Stain Nothing!!!!

Good technical posts.