[Benning Boy]

So I see these dog tag sized/shaped knives, and they're made of titanium.

I've read that it's impossible to keep an edge on this material, hence most knives that have titanium as an ingredient use it only as a coating or handle material.

What makes titanium such a bad blade choice?

[spittinfire]

Titanium is very resistant to corrosion but it doesn't have the hardness of steel which is needed to retain an edge. It can't be heat treated like steel which is where the hardness issue comes in. It also tends to be more brittle so it would break long before steel. If you don't mind sharpening on a more regular basis it's not really a problem. It also depends on what you want to cut.

[Dillinger]

I have a couple of Titanium knives from Mission Knives. Yes, it is harder to get a hair shave edge on there. It's Titanium after all.

However, I haven't had edge retention issues. Granted, I haven't put my regular field knife through all the constant assault that I have in our knife tests, but my main field knife is over 6 years old and it still has a good edge on it.

I don't know if the blade would break sooner than steel. I suppose it's possible, but this thing is a workhorse of a blade. I have chopped and pryed with it and there is almost no sign of wear.

MPT12-Ti Titanium Knife [MPT12-Ti] - $379.00 : MissionKnives.com, The Toughest Knives in the World!

As for what a Titanium Knife can ENDURE:

Here's four ( or five ? ) years of salt water immersion

mission knives |

[skullcrusher]

It actually depends on actual alloy composition and grade of Ti used. For instance a fairly common type of Ti is 6Al-4V Gr5: meaning 6% Aluminum and 4% Vanadium Grade 5. Relativey soft, very tough and great corrosion resistant composition. Ti is a super alloy and machinable. The dust or small savings of Ti are easily flamable, but as a solid, it has a high flash/metlting point.

Not sure I'd trust a hardened Ti blade to rigorous abuse.

[Franciscomv]

Benning, unless you need a lot of rust resistance and a non-magnetic blade, I'd stick with steel. Titanium knives are quite pricey, just use the Mission website as an example and check the price of the same knife with a steel blade and with a titanium blade.

Also, if you're anal about edges, you're not likely to be satisfied with titanium. It just doesn't give you the same performance as premium steels with good heat treatment.

However, when you do need their particular qualities (light weight, rust proof, tough) Mission titanium knives are great tools. I volunteer with local SAR groups and I use a MPU-Ti when we've got to work in flooded areas, helping the army and national guard rescue groups. The knife might stay wet for days (I've had Leatherman tools just fall apart on me!) and be used for all sorts of ugly tasks. My MPU might not get as sharp as one of my D2 or S30V customs, or stay sharp for as long a time, but it takes a lot of punishement and keeps coming back for more.

I put a slightly rougher edge on titanium than on steel, and it seems to last a bit longer than a more polished edge.

[Benning Boy]

I smell a stump the Francisco thread coming, if he is agreeable.

Thank guys, this cleared up alot in a few short posts.