S7/5160/L6/52100 = tougher than infi?

S7 is tougher than INFI and 5160 may be as well but it all depends on the HT and hardness. I believe in their normal states INFI is not as tough as S7 or 5160. However toughness does not always equal damage resistance. A knife made out of ultra tough 5160 at 55RC will probably be more easily damaged than a knife made out of 52100 at 60RC. 5160 at a lower RC may roll an edge when chopping thorugh a really hard knot in wood while the higher hardness 52100, which is less tough will probably be more damage resistant when chopping wood and suffer no edge rolls or chips when it hits the knot.

Tell the guy toughness does not always mean damage resistance. S7/5160/L6/52100 and INFI are all REALLY tough steels that have a threshold for lateral stress etc.. that is likely greater than anything the blade will ever experience in normal use.

People get really hung up on "toughness" and don't take into account that toughness only really benefits a knife to a certain degree because only so much toughness is needed. INFI is great because it provides solid edge holding with stainless-ness while being tougher than you would ever need a blade to be.

Ive taken SR77 blades and SR101 blades and beat the hell out of them and while S7 is tougher than 52100, I would never know it because both of them are sufficiently tough.

Im not sure about carbides and what not maybe Mete can chime in!
 
I think that you are wasting your time arguing with a guy who hammers knives with a steel mallet and breaks 'em with a 2x4. :p ;)

The question is rather broad... Tougher how? At what Rockwell hardness? ...At what thickness? ...At what edge angle? Lateral strength, flexibility, edge retention, malleability, etc...?

To me, INFI is the best all around steel. Other types of steel may each surpass it in one or two different categories, but will not in others.
For example, if a knife in INFI strikes its edge against something harder, its edge may roll or dent while another type of steel might chip out or crack. Rolls and dents are easier to repair back to a good edge and with less metal lost.

And no matter what type of steel, the heat treat protocol is a crucial part of making a type of steel be all it can be. Busse has one of the best for the types of steel they use.

:)
 
on the nitrogen issue, nitrides will contribute carbide-like performance without imparting high-carbon corrosion properties because the nitrogen behaves nothing like carbon in regard to oxidation.
 
Jaxx said:
I think that you are wasting your time arguing with a guy who hammers knives with a steel mallet and breaks 'em with a 2x4. :p ;)
Click to expand...

just watched the video. Folders no less! Hope those gloves were fancier than they looked.
 
http://www.ndt-ed.org/EducationResources/CommunityCollege/Materials/Mechanical/Toughness.htm

It's always been my understanding that when people say "s7 is tougher than INFI", what they are actually saying is that it is more ductile under shock loads. Yes, S7 will deform more than INFI, but it will do so with lower amounts of force. It may be able to resist fracturing or breakage if the rockwell is kept comparably low, but again under lower levels of force, and you will end up with a bent/deformed knife. As a matter of strength combined with ductility, INFI tends to be the highest of the lot because it's difficult to manage both.
 
Also, I think that your reading his statements in the light of "This steel is overall better", rather than a literal interpretation of what he is saying. INFI is in fact not the best steel for all applications, Jerry himself has said that INFI is not a good choice for knives with thin cross sections (such as thin slicer/hunter/skinners). This is one of the reasons why they are experimenting with trying to get INFI to a higher hardness. INFI is also not immune to fractures and breakages, where, if thats what you really need (things like jack hammer bits), other steels can provide you with that. They will tend to mash and dent all over the place, but will avoid catastrophic failures.


http://www.bladeforums.com/forums/s...menting-With-INFI-.-.-.-.?highlight=thin+infi
Jerry Busse said:
We have been experimenting with a new heat treating procedure for INFI that we have termed CNQ which promises to deliver a consistently higher hardness as well as, what we hope will be, a considerable increase in cutting performance on certain materials.

Of course, the incredible toughness that INFI brings to the table will be decreased, but we recognize that there are some applications where exceptional toughness is not a top priority. . . .

We will keep you updated . . .

Back to drinking. . . .

Jerry



.
Click to expand...
 
Last edited:
I was trying to find the particular qoute from jerry regarding thin cross sections, but here is a good qoute from him regarding d2 being a superior choice to sr101 in thin cross sections, which can directly be trasnlated to INFI as infi is similarly maleable, but has a comparably unstable edge when thin when compared to d2.

I mean this not to down your arguments, only to show that when you are looking for a particular set of performance perimeters, INFI can and does fall behind. It's prowess is in having high marks in all categories, not having the highest in any one of them.

http://www.bladeforums.com/forums/s...f-Hunter-Utility-Knives?p=2152304#post2152304
JenniferBusse said:
Jerry:
---
“
In extremely thin edges, such as are planned for the Hunter/Utility line, D-2 will prove to be a superior choice. The same qualities that make SR-101 a great steel for abuse, play against the house when it comes to extremely thin cross sections. Under contact (cutting not chopping) with harder materials such as metal banding, bone, rock, etc. . . SR-101 will roll whereas D-2 will prove to be the clear winner in these applications. However, if you do any heavy lateral stressing on a thin cross sectioned D-2 blade, you may be glad that your Swamp Rat D-2 blade is backed by the best no BS warranty in the industry! ;)
Click to expand...
 
http://www.bladeforums.com/forums/s...uestion-About-Thin-INFI?p=8119999#post8119999

a generally excellent post regarding the properties of INFI. In particular to this discussion:
sandgrouper said:
This last property relates to what is generally meant by toughness. Again, they are related properties measured in different ways. UTS/yield/% deformation are measured by the bar stretching machine and tell you a lot about what you want to know. Toughness is normally measured by taking a specially shaped pin and breaking it in two with a hammer machine. The amount of energy absorbed from the hammer in breaking the sample is quoted as the toughness. The higher the value, the tougher. So a glass rod can be hard and have a high yield but because it won't deform at its yield point, it breaks and absorbs no energy so it is not tough. A low to mid-carbon steel can be made pretty hard, but not very hard, so it will have a moderate yield, but will deform a long way at that stress and so absorb a pretty high amount of energy and be declared fairly tough. Something like INFI that has a very high yield and still deforms a lot without fracture will be very tough.
Click to expand...


This is where I think if you really look at the core concept of "toughness", INFI does stand above steels like s7. s7 may be able to deform to a greater extent and thus absorb great amounts of energy, but INFI can do with less deformation.

(P.S. - I don't really know what I'm talking about, having no education in this subject at all. I'm just regurgitating other peoples educated posts/opinions o_o )
 
I wouldn't bother arguing so much about one specific alloy over another, you don't see too much of a difference in toughness between Bussekin blades. I would argue that Busse does the best heat treat in the business.
 
I make it a point not to argue with people on YouTube, regardless of the topic. The anonymity of the internet breeds stupidity.
 
True true on the heat treated elements. No steel will perform to its potential without proper hardening protocol. Luckily, the Busse family continues to try to better its steels by evolving the heat and freeze treatments.
 
Nitrogen does impart corrosion resistance. The Germans used it during WWII when their chromium supply was limited. I'm not sure how effective it is compared to Cr, but it does improve it enough to be an alternative when circumstances warrant it.

He's half right in that carbides equal rust, not rust resistance, but only if they're chromium carbides. It is fairly common to put other elements in stainless steels to form carbides first, and leave the chromium alone. Once chromium is combined in a carbide, it can't contribute to corrosion resistance.
 
Ok! I don't chime in often, I'm no Science guy, computer guy or whatever!, I've been into and using knives for a long time ( 39 years ) and when I got my first MS in A2! I was blown away! it out was FAR BETTER! then anything I had ever used! INFI raised the scale! from that! Anyone who has anything to say should USE! knives for real! This armchair knife shit is worthless!
 
I'd love to hear exactly why nitrogen increases corrosion resistance. In INFI I know it's used as a way to increase hardness, and having a low carbon content (.5%) it's 8% chromium results in a stainless like free chromium level of 3%, which floats in the matrix to create the chromium oxide passivization surface layer... but the nitrogen part, I haven't heard a clear description of what exactly it does.

Like this article:
http://www.keytometals.com/page.aspx?ID=CheckArticle&site=kts&NM=202
which explains what nitrogen does, but not really how.
 
After watching the destruction test on Knifetest.com, I am well aware of the abuse a Busse knife can take. Much more than I can ever envision, in any "practicle" application I would use the knife for. Combine this with the lifetime replacement warranty, it's pretty darn hard to beat. I have complete confidence in Busse knives, and that is good enough for me.
 
You must log in or register to reply here.
Back
Top