Stainless Knife Steels: 440A vs. VG10

I have a passing interest in the history of both official and unofficial knives used by the US Military throughout history. In WW2,  the Marbles Ideal Knife was never official issue, but was known to be carried in every theater of operations. The Ideal pattern knife had been around for decades by the time WWII came about, and wouldn't have been out of place in any deer camp in America. This made the Marbles Ideal Knife a boyhood dream knife for many an American youth, up through when the Marbles company failed financially and essentially exists only as intellectual property. That being said, the current owner of the Marbles IP offers a modern take on the classic Marbles Ideal pattern knife: 

https://amzn.to/45scaYN

At $16 at Amazon, that Marbles knife is $10 less than what I paid for mine. But what does your $16 get you? Some 440A stainless steel, in a thick blade, with a rubber handle and a sheath to house it. However, that’s almost all you get with a nearly $90 Cold Steel SRK made in San Mai.

https://amzn.to/45se7EB

Cold Steel has been making the Survival Rescue Knife (SRK) pattern for decades and in many different steel types. It's even advertised as the Navy SEAL knife for sailors going through BUD/S (Basic Underwater Demolition/Seal training).

So what gives? 

What makes one a $24 knife and the other a $90 knife? Is the price worth the difference?

First, the Marbles Ideal is a Chinese knife, and the Cold Steel SRK San Mai is a Taiwanese knife; the difference in country of origin reflects in the price. 

Second, the Chinese 440A stainless steel blade is a standard cutlery stainless steel with a decent carbon content,  and depending on the heat treatment it can be awesome or awful for edge retention (the awful reputation comes from a lot of cheap gas station/flea market knives using 440A with a bad heat treatment). The SRK San Mai has a VG10 steel core, which is sometimes called a "super steel" due to toughness, corrosion resistance, and edge retention. Lots of producers make 440A, but there is only one producer of VG10, so that is reflected in the price difference.

Comparing the steels by chemical makeup, VG10 has more carbon but less chromium, and also has a significant Cobalt content in the alloy. This means that 440A is theoretically slightly more rust resistant, and VG10 is going to have better edge retention at a given hardness level (more carbon to make carbides in the steel matrix). In practice, this means you’ll need to sharpen the Marbles Ideal knife slightly more often than the SRK San Mai. You can’t tell the different by eye or feel; you'll need a chemical assay to do that for you.

Finally, market forces. The Marbles brand may have been a big name in outdoors publications decades ago, but not anymore. On the contrary, Cold Steel has been a big name in the knife industry for decades, and brand equity is a thing, so that reflects in the price as well.

What does this mean for you?
In my experience with both knives, they are both going to get the job done. The Marbles Ideal has a better belly for skinning large game and the SRK has slightly better edge retention. I’d take either one with me into a salt water environment and expect no problems, given the very high chromium content of both blades. However, that same high chromium content combined with the final edge hardness makes sharpening with traditional stones a very poor life decision, so I would use a diamond stone when sharpening both knives.

Given that both work, have good edge retention, which one is better and why?

The SRK is better, because the handle is more comfortable, and the edge retention is slightly longer. The sheath is also a better design in my opinion, but that’s largely irrelevant. However, is it over three times better? No. The Chinese Marbles Ideal knife offers great utility for your money if you're pinching pennies and need a nearly 7” stainless steel Bowie style outdoorsy knife to do outdoorsy stuff. If you could only have one tool, a 4-7" Bowie style fixed blade isn’t the worst option to take with you.

However, if you are in the market for a knife to use as a general cutting tool for a Get Home Bag or use around the homestead, it is hard to beat the Mora Companion which has a more comfortable handle than either the SRK or Ideal knives, and while the blade is much thinner at 1/8th of an inch, that means it is that much lighter on the belt or in the pack. It also means it's the absolute best knife here for food preparation (I know, I've tested all three). The Sandvik stainless steel blade is the softest of the three, but that means it can be sharpened more easily, and by conventional stones, no need for a diamond stone.

It's heavy and thick, but if you need a "big camp chore knife", then for the money the Marbles Ideal really is a great value.