Best for specific use

[Serra_Avatar]

My focus is straight-razor edge retention (or as close as I can get to it...) and corrosion resistance(so it can be taken into many different environments). This knife's specific use is to be a fighting arm, meant for cutting/stabbing flesh.(or anything else a fighting blade might have to go through durings it's duties) What would be the best steel to use for this knife?

I’ve singled out three steels. Two of them I’ve heard a little about and if I understand correctly they are classified as "stainless steels", ATS-34 and S30V (I want to stay away from 440C, didn't work for my tastes in the past)

the last steel I selected is 154CM. I selected it as part of my original three because I’ve had good experiences with it. It didn’t rust when I touched it with sweaty hands and forgot to wipe it off after a day or so. I took it to the beach and it didn’t rust at all even after a full day in salt air. I can get it sharp enough to shave with and it can pass cleanly and smoothly through a horizontal, free hang piece of 8.5 x11 peace of computer paper so it has at least the edge I want.

Any thoughts or suggestions would be appreciated,thanks.

 

[Stacy E. Apelt - Bladesmith]

Lets start with the steel.154CM is the same steel as ATS-34 ,one is made by Crucible,the other Hitachi.The newer CPM154 would be a better choice over either of the two.S30V is excellent.Very non corrosive and gets HARD.
About the knife -
You don't put a straight razor edge on a combat knife.As your post title stated - SPECIFIC USE - a straight razor edge is designed to cut very low friction and thin slices.It is hollow ground at 10 degrees or less.A combat edge has a much steeper angle to increase the edge durability.A combat edge is often flat ground with the final bevel at 18 to 20 degrees (often as high as 25 degrees).The term "Straight Razor Edge" can easily be misused when one means "Razor Sharp".Razor sharp is a term meaning the knife is capable of taking a very sharp edge and has been sharpened properly for the edge it has.An Axe can be razor sharp.For combat situations ,durability is far more important than being able to shave with.The knife should be able to survive rough use and still be capable of use later on.The Axe analogy works best here.If you ground an Axe with a 10 degree hollow grind,your first two or three chops would be amazing.Then it would slow down and stop cutting at all.At a 30 degree convex grind it won't seem nearly as sharp.But you can cut all day long with it.It isn't as "sharp",but thousands of times more durable.The real point about combat weapons also applies to the Axe example.Both edges would be terrible to be hit with.The razor edge would kill the first couple of barbarians,and then would get pretty dull.The fatter grind would take on the Mongol horde, and still cut your roast leg of Ox for dinner.

If you want a REAL combat knife,my recommendation for your knife would be :
S30V with cryo HT.Flat grind with 20 degree edge.Moderately thick spine (1/4").Moderate distal taper,keeping the tip fairly thick,to keep breakage risk low.Taper the full tang to keep the knife forward weighted.Black G-10 scales.Kydex sheath.The blade can be matte finished,black coating on the blade looks nice but is unnecessary - it is the handle and sheath you want black.Once you unsheathe a weapon,you want the enemy to look at it.(this does not apply to mall ninjas)
Stacy

 

[Serra_Avatar]

To me the term "combat" would mean I'd do more than just fighting with it. IE- digging, prying occasionally, opening something...utility stuff.

What you posted does make more sense though. I didn't have a "combat" knife in mind...just a people filleting/ skewering "razor blade".

Thank you for that information on the steel and edges. I think it convinced me to make a couple changes to my idea. ( I already agree on the G10 and Kydex though! )