Proprietary steels


June 15, 2008, 01:01 AM
Right off the top of my head I can think of two manufacturers who use a proprietary steel. Well, only one still does: Busse Knives uses their Infi steel. Cold Steel used to have their Carbon V but it has been replaces with SK-5 (which I've not heard of.)

Is anyone here familiar with the properties of these steels? What do they compare to and what are the elements in them? Are there other manufacturers who use some type of steel they laid claim to?

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June 15, 2008, 10:27 AM
Carbon V is essentially 0170-6 or 0170-6C as it was called by Camillus, IIRC. Camillus was the supplier to Cold Steel. When Camillus went under, CS was forced to find another steel. Thats where the SK-5 comes in.

The same steel is sold as CV (Chrome Vanadium) by Case.

Carbon V was more of a marketing thing than a proprietary steel.

June 15, 2008, 11:34 AM
I agree with Ruperstris. Infi is the only thing out there that isn't only renaming/marketing.

If you think about it there's very little chance that a "proprietary" steel actually is in use by a knife manufacturer. They may use a steel not used by anyone else and market that way, but there's a lot of expense going to having a steel manufacturer formulate a specific run just for you.

June 15, 2008, 11:50 AM
Does Busse make their own steel (I'm sure that they don't)
and do they buy 40-50Klbs of steel at a whack from whoever does make their steel?

If not then I am real sure that Infi is just someone elses steel repackaged for marketing too. The chemical analysys shows it close to CPM 3V with a tad less Chromium a lot less vanadium and just a dab of nickel. Total analytical difference less that 1% with the exception of the vanadium which is 2.4% less than CPM3V.
In any case I don't think they have it made to spec, they buy it on spec, ie. not "proprietary"


June 15, 2008, 02:42 PM

My understanding is that they had it made to their specs and that they do buy it in quantity. To my knowledge no knife company makes the steel themselves, they all buy it from a steel manufacturer. If you've not gotten your info from the source and I haven't either we're both repeating what we've heard. I'll try to call them next week and see if he'll tell me himself whether they discovered a nitrogen steel and started using it for blades or if they had a steel modified with nitrogen.

June 15, 2008, 04:58 PM
Works for me hso BTW if you are looking for some comparative analysis look here:


June 15, 2008, 05:42 PM
Strider recently worked with Crucible with NiTiNOL
NI (Nickel) TI (Titanium) NOL (Naval Ordinance Laboratory)

from Mick :
It was invented years and years ago by a guy working on the nose cone of a missile.

Strider Knives, (really Duane) along with the wizards at Crucible decided to re-make the stuff, only better.

Strider knives is VERY proud to be the first company in history to offer blades made of this material.

Its basically Ti that hardens to 65 RC.

Pricey stuff though. $200 a pound

Brian Dale
June 15, 2008, 08:45 PM
Nitrogen? :confused: How would you get nitrogen into the alloy, hso? It seems like an opportunity for all kinds of weird things to happen. I admit that it's way over my head, to start with. My analytical chemistry days were spent banging on huge, organic molecules.

June 15, 2008, 09:15 PM
In my book "Proprietary" means that only you have it and sell it.
When anyone can make it and sell it it isn't proprietary any more, even if it has a different name.


June 15, 2008, 10:07 PM

Not sure how they do it but Spyderco's H1 also contains Nitrogen in place of Carbon. AFIK, it increases hardness like carbon does but it doesn't let the steel rust/stain like carbon does.

From A.G.Russell:
H1 Steel
H1 steel is a stainless steel that is precipitation-hardened and contains nitrogen instead of carbon, which cannot rust.

Carbon-0.15%, Chromium-14.00-16.00%, Manganese-2.00%, Molybdenum-0.50-1.50%, Nickel-6.00-8.00%, Nitrogen-0.10%, Phosphorus-0.04%, Silicon-3.00-4.50%, Sulfur-0.03%



Brian Dale
June 15, 2008, 11:00 PM
Every single day, Rupestris. ;)
Thank you.

June 16, 2008, 12:14 AM
The other thing to keep in mind is that INFI is the specific alloy coupled with a very specific heat treat recipe that was developed by Jerry Busse.

But Jerry is not immune to marketing-speak. See Swamp Rat's SR101 (aka 52100) and Scrapyard's SR77 (aka S-7) for examples thereof.

Rick (a bit of an INFI nut myself)

June 16, 2008, 07:25 AM
Nitrogen steels have been used in Europe for years for corrosion resistant steels that are hardenable like carbon steels. American companies like Spyderco and Busse started using them in recent years.

Cobalt allows, not really steels, like Stellite and "Talonite" started out being used by a few makers and then Camillus (on a few knives). The stuff can't rust since there's no iron in it, but it's so difficult to grind that it isn't really suitable for a manufacturer to use much.

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