Qualities of Bussekin steel

[ThornStrike]

Obviously there are three types of steel used by Bussekin knives: SR-77 (mostly scrapyard), SR-101 (mostly swamprat), and INFI (mostly busse)

I really don't need to tell you all that

I've watched the videos, read the reviews, and seen the pictures that all attest to the awesomeness of these steels

My question though, is how do they compare to each other?

I own knives with all three types of steel, and I have read enough to know that is generally understood that SR 77 has superior stregth, laterally and otherwise and SR 101 has superior edge retention. I also know that INFI is that "super-steel" that doesn't chip, can be easily fixed from bad rolls, is super strong, etc. etc.

However, I have never seen a direct comparison of the steels that compares the qualities of each steel as it applies to each property of the steel

For example, SR 101 edge retention > SR77 edge retention, but is it better than INFI edge retention? how does the lateral strength of INFI compare to SR77?

I guess, if I'm not making myself clear, what I want is your comparison and opinions of the steels, that talks about each quality as it applies to each steel, rather than just pointing out the strengths of each steel.
If I'm still not making any sense let me know and I'll try to rephrase

I appreciate your opinions!

 

[amflud]

Hmm....I would rank them accordingly.

Toughness: 1. SR77 2. INFI 3. SR101
Edge Holding: 1. SR101 2. INFI 3. SR77
Ease of sharpening : 1. tie between SR77 and INFI 3. SR101
Corrosion resistance: 1. INFI 2. SR77 3. SR101

SR77 is only slightly tougher than INFI, and SR101 has only slightly better edge retention than INFI. I would say that INFI is the perfect compromise between SR101 and SR77 coulped with much better corrosion resistance than either steels.

 

[Jason B.]

SR-77 is S7 tool steel commonly found jack hammer bits, tough stuff but I have never used it so I can't really comment.

INFI I haven't used either but have sharpened a few times and in that perspective its a dream to work with.

SR-101 is my favorite steel, SR-101 is 52100 ball bearing steel and like all busse steels have a very good heat treatment. As I understand it has the best edge retention of the 3 and is very tough but known to chip at the edge if pushed hard, how thin or thick your edge is will play a big part in this though. The edge retention of 52100 depending on HT can exceed even the best of super steels at times.

Its probably the hardest to sharpen of the 3 but will get to levels of sharpness that will make you scared of your own blade. Rust resistance is low so corrosion will happen fast if uncoated. Lateral strength? not sure but I say SR-101 might have the least.

 

[Last Visible Canary]

Hmm....I would rank them accordingly.

Toughness: 1. SR77 2. INFI 3. SR101
Edge Holding: 1. SR101 2. INFI 3. SR77
Ease of sharpening : 1. tie between SR77 and INFI 3. SR101
Corrosion resistance: 1. INFI 2. SR77 3. SR101

SR77 is only slightly tougher than INFI and SR101 has only slightly better edge retention than INFI. I would say that INFI is the perfect compromise between SR101 and SR77 coulped with much better corrosion resistance than either steels.

on what are you basing sr77 having higher toughness than infi?

'Malleability
A metal that can be hammered, rolled, or pressed into various shapes without cracking or breaking or other detrimental effects is said to be malleable. This property is necessary in sheet metal that is to be worked into curved shapes such as cowlings, fairings, and wing tips. Copper is one example of a malleable metal.'

'Toughness
A material that possesses toughness will withstand tearing or shearing and may be stretched or otherwise deformed without breaking. Toughness is a desirable property in aircraft metals.'

While both sr77 (modified s7) and infi have malleability and toughness at high hardness, it's always been my understanding that it takes more force to cause infi to deform than it does sr77. Likewise, it takes more force to make infi take a set during bend tests than it does sr77. Both will bend before breaking, and both will deform before shearing, but infi requires more force before doing so.

What experience or tests are you drawing upon to say otherwise?

 

[amflud]

on what are you basing sr77 having higher toughness than infi?

I was only speaking on my personal experience. To me it seems that my INFI edges tend to roll only slighty more often than my SR77. I wouldn't say that any of them have ever failed. To me, INFI is as close to being the perfect steel as you will ever find.

 

[Last Visible Canary]

SR-77 is S7 tool steel

SR-101 is 52100

Both of the sr-xxxx steels are modifications of their original formula's, I believe both have additional chromium. They are based on the original steels
of s7 and 52100, but their compositions are slightly different.

but known to chip at the edge if pushed hard, how thin or thick your edge is will play a big part in this though.

I've seen 3 blades that I can recall that have chipped, one of them was on a penny nail with a thin edge, another was on frozen hardwood with a
very thinned out edge - and if you look at that photo of the edge it is also dented and bent all over the place (it didn't just chip, it bend like crazy
before doing so), and one other I'm having a hard time thinking of. I'm thinking the third instance was the skeleton key the guy hammered into a log
and kicked, in that instance as well the steel bent, took a set and then sheared away rather than chipped. So really I think it's only 2 that I've seen
where I was positive that it 'chipped', as in a fracture that ran along the grain of the steel and ejected the metal in a similar fashion to glass. Infi
will chip, but under crazy hard impact, generally on a very small bit of edge. 52100 is more likely to chip as it has the lowest malleability of
the three (I recall one where the guy was chopping hardwood at night and it took big rounds of metal out of the edge). I haven't seen many examples
of sr77 that's been extensively damaged so I don't know what it's limits are, but I would suspect that it would be the least likely to chip - but also
the most likely to bend and dent out under low force.

From the descriptions jerry has given over the years, I would describe the three steels something like this:

Infi - excellent edge holding on soft targets like woods. High malleability with high strength, it takes a lot to get it to bend and dent. The best all
purpose steel of the three.
because of its malleability and high hardness, infi has a kind of 'self sharpening' affect on softer woods where the wood will just kind of pushes the
metal down on each side rather than blunting the edge. it will get a little dull and just hover there for a long time. On harder abrasive materials, I've
read that sr101 takes the lead.

sr101 - The most stable edge when thin. However it's also the most likely to chip, it's the best of the three if you know your going to be hitting hard
targets like bone but you want it to keep it's edge as long as possible. Has to be differentially hardened for maximum strength because of this, it is
the most likely to break under heavy impacts.

sr77 - the highest malleability of the three. This means it is the least likely to break under hard impact, but it is the most likely to dent and mash out
first. It's great for beating the crap out of, but it's the worst with thin edges because of it's malleability. that's not to say it's soft, it takes significant
force to get it to deform, but it will do so with the least force of the three.

I would assume from what I've read that it would go infi, sr101 and then sr77 as far as corrosion resistance, but I've never paid enough attention to
the posts regarding rust to really have a good idea of where the three stand against each other.

I'd asume that the lateral strength of the steels would go infi>sr77>sr101. infi will take a lot of force to bend and bend so much before snapping. sr77
will take less force and take a higher degree of bend. sr101 will probably take more initial force to cause deflection than sr77, but will snap at a shallower
degree and with less force at the end than sr77. That is total conjecture on my part though, as I can't recall reading any posts regarding the defelction
rates vs. force applied on the three.

 

[Jason B.]

The only chip I've ever been able to put in my SR-101 blades was intentional and can be found in my sig. I have experienced the deformation and tear out like you described when hitting a large staple on a heavy swing though. Didn't know it was modified, thought it was just well done (HT) and renamed for business sake. Thanks for the run down.

Need me some SR-77 next, the DF is calling my name

 

[Last Visible Canary]

This is the kind of chip I would expect out of sr101 that I wouldn't expect out of infi or sr77, note the
smooth fine grain structure

as an example of how I'd expect sr77 to take a deformation where I wouldn't expect infi or sr101:

The deformation goes farther into the main grind than I'd expect of the other two. Given, the dfle has
a thinner edge than you'll find on any of the scrap yard offerings - the scrap yards I've handled (dumpster
mutt and dog father) were both very thick at the edge.


This is the kind of "chip" I'd expect out of infi, which is actually the metal sheering away. In this case the
user hammered it into a log and kicked it.

This was a game warden that was bent while pying, and then when the user was trying to hammer it flat
again it snapped. For what it's worth, it did take a set initially. without a better close up of the edge I can't
really comment on it, but this particular game warden is one of the thinner tips busse makes, I would have
expected sr101 to have snapped earlier than infi, and sr77 to have bent more and with less force, but probably
returned to straight without snapping.

I don't have a pic of it, but there was one posted where (I beleive it was an ash1) the edge hit a peice of rusted
chain, and jerry's comment was that the edge looked more like a sheer than a chip.


The battle rat I recall having taken big chips was probably a heat treating problem, combined with hard 2" dried
branches and a lot of off angle strikes from chopping at night. They were big enough that the guy was using
it as a saw to make notches in the wood he had. I believe it was over hardened, but there was never a
statement made about what the problem ended up being, only that it was a fluke one time occurrence.

What I don't expect out of infi, sr101 or sr77 is big chips like these:

all knife steels will break, bend or chip, but each one has a different type of deformation and failure that is unique
to that steel, at that hardness, with that type of heat treat. If you take 1095 and put it at 62rc, you'll likely see
chips like the above. If you do a cryo quench as part of the initial heat treat to help martensite conversion, it will
still probably chip like the above, but it might take more force to do it. sr101 and sr77 both took steels that already
had known properties and tried to increase toughness as much as possible without dropping them below 57rc. They
will act a lot like their parent steels 52100 and s7, but with higher toughness at their given hardness value. 52100
is chippier than s7 but holds a better edge, and s7 is mashier but will tend to avoid chipping. Infi is in the middle,
where it holds a better edge than s7 and takes more force to bend, but may be a little more likely to actually snap
and tear out than s7. It will avoid chipping and snapping better than sr101 and take more force to do either of those
when it eventually does - but it doesn't hold as stable of a thin edge, especially against hard targest like bone.

 

[Jason B.]

Great pics and examples, that BM and becker though..... wow! dat be a chip!

I like to test my knives and edge geometrys to make sure they don't fail to my uses but I don't abuse them so failures like shown are something I don't think I'll ever see. I have some 200x magnification pics of my regulator I'll throw up in a bit, shows great detail of deformation and tear out.

 

[resinguy]

Both of the sr-xxxx steels are modifications of their original formula's, I believe both have additional chromium. They are based on the original steels of s7 and 52100, but their compositions are slightly different.

Modified, really? Has that ever been explicitly stated by Jerry, or some metallurgical data presented here? It seems to me that if he was getting a modified recipe of a standard steel, then his raw material price would be higher. I always figured that the SR steels were just a branding thing, to reflect the Busse heat treat.

 

[Jason B.]

I think its only 100x and not 200 like I said above but either way I think it a good shot

I was splitting a 2x4 with my Regulator and hit a large metal staple. Didn't cut the staple but did a number to the edge, I was surprised too because it was a thicker convex bevel The secondary bevel you see is from touch-up while camping and unfortunately removed the excess deformation.

Not so close up.

 

[Last Visible Canary]

Modified, really? Has that ever been explicitly stated by Jerry, or some metallurgical data presented here?
It seems to me that if he was getting a modified recipe of a standard steel, then his raw material price would be higher. I always
figured that the SR steels were just a branding thing, to reflect the Busse heat treat.

it was explicitly said by Eric Isaacson regarding sr101 on the swamp rat board. I can go look for the post in a bit.

I was splitting a 2x4 with my Regulator and hit a large metal staple. Didn't cut the staple but did a number to the edge,
I was surprised too because it was a thicker convex bevel The secondary bevel you see is from touch-up while
camping and unfortunately removed the excess deformation.

on the regulator, the secondary bevel did remove a mashing/rolling/bending of metal around he damaged area right? I would expect sr77
to deform a fair bit before sheering or chipping away, where I'd expect sr101 to be the one to just chip away without deformation if any of
them were likely to do it at all.

 

[Last Visible Canary]

SIGH

and now that I look for the specific post I'm having a hard time finding it. I'm wondering if it was on the swamp rat home forum, or if I'm just crazy.

http://webcache.googleusercontent.c...2100+"eric+isaacson"&cd=7&hl=en&ct=clnk&gl=us

That's an example where RokJok stated that it's a different composition and Eric commented on his post directly without disagreeing with his statements.
RokJok has said even more explicit in other posts that included Eric that it's a different metallurgical composition, but this is an example where Eric
commented on the post directly. I'll keep looking for the one I'm thinking of, where Eric makes a quick but direct statement on the issue.

I may be thinking of a secondary source, rather than direct, it may have been that Cobalt said that he talked with Eric directly and got that information...

[edit: yeah, I think the initial source i was thinking of was cobalt, who got his information from a long time knife maker, and then I bolstered it by the linked post by eric isaacsan below]

 

[Last Visible Canary]

http://www.bladeforums.com/forums/showpost.php?p=4601587&postcount=6

Oh, that's a beauty. Blade material is SR101 our proprietary steel(a modified 52100). It has a Double Cut finish
on the blade, which means it is similar to a Bead Blast but much finer grit is used to help seal the pores.

Nice knife, congrats

I had thought eric stated specifically what chemical was added to it, but all I'm seeing in my search is commentary from RokJok, Cobalt, t1mpani
and SteelNut. I wish I had the swamp rat home forum to search through.

 

[Last Visible Canary]

In the case of 230grains sarsqautch, we see what happens to infi when brought down to a very thin edge and chopped on frozen hardwood, which can
act almost like a ceramic at times. The edge rippled, dented and tore all over the place, which is what I would now expect (having seen it here). I would expect
sr101 might have a few chips here and there but with overall similar damage, and sr77 to be even more dented and rolled, with more of the damage
getting up into the main grind.

While most of the pics are doa from this thread, there are still two good images of swamp rats d2 being brought near destruction:
http://www.bladeforums.com/forums/showthread.php?t=322561

Here are the pics from the some of the testing we did on the Bog Dog and the Safari Skinner. Both of these knives had a
Rockwell hardness of between 61-62. Remember that D2 is not supposed to have much lateral strength at that high of a Rc. Also it would normally chip
out with extreme impacts to the edge as it is more of a cutter not a high impact steel.

As the pictures show, the Bog Dog has a significant flex and the Safari Skinner pics were taken after a 275 lb Deputy Sheriff spent 1 1/2 hrs pounding on it
with a hammer. The edge has rolled but is not chipped out like you'd expect (and even more important it isn't in pieces) and you can even see the area on
the side of the blade where it was impacted with the hammer. When finished the hardened face of the hammer actually had gouges in it from the knife.
These pics show that we have achieved a large amount of malleability of the edge(which is uncommon for D2)

Also some makers don't think that D2 performance can be increased by a deep cryo treatment, I think that these tests prove differently. We have done
testing on most of the other D2 blades out there from many many makers and none of them come even close to this level of toughness or durability.

We do these tests so you don't have to
In the past, we have probably been overly cautious when discussing the abilities of our D2 blades, but now you can really see what they can do. We get
this type of performance because of our proprietary Heat treat and deep cryo cycles.
However, please don't try to break them just so you can say you did.

Toughest D2 blades on the planet
http://home.insightbb.com/~e.isaacson/bog_dog_flex.jpg
http://home.insightbb.com/~e.isaacson/Skinner_beating.jpg

http://home.insightbb.com/~e.isaacson/Skinner_Beating3.jpg

http://home.insightbb.com/~e.isaacson/Skinnerbeating5.jpg

How did the edge of the Bog Dog look after the bend test?

At this point, when the picture was taken, the edge was undamaged (uncracked) and the blade would return to true. We did continue to bend it to destruction

and at that point the blade had taken a set, which in itself is unbelievable because D2 normally will not take a set but will just break(and break with very little bend).

I hope this helps

Actually we are not just saying that's what we did we are actually showing you we did it in the pictures that are posted.
That's one reason we post the pics, a lot of people can say there knives perform, few actually show you that they do.


The face of the hammer! The spine of the knife was placed on the anvil with the edge up. Then the edge was pounded with the face of the hammer. I hope that helps.

Theres a big chip/chunk taken out of the spine and a broken tip. If there were still pics up I'd like to get abetter idea of what the edge looks like, how much of it is
actually mashed down vs. chipped off to form a square edge that was then mashed and smoothed out by the hammer. swamp rats d2, as per jennifer/jerry, sits above
all of the other steels in it's ability to hold a thin edge, giving it greater edge stability against hard targets like bone. i would assume it's wear resistence is at or above
52100 on abrasive media, putting it above infi as well. However, it doesn't have the same lateral strength, and has less shock resistance/toughness.

some more info on swamp rats d2:
http://www.bladeforums.com/forums/showpost.php?p=2152304&postcount=1
http://www.bladeforums.com/forums/showpost.php?p=2153338&postcount=6



.

 

[Last Visible Canary]

Modified, really? Has that ever been explicitly stated by Jerry, or some metallurgical data presented here? It seems to me
that if he was getting a modified recipe of a standard steel, then his raw material price would be higher. I always figured that the SR steels were just
a branding thing, to reflect the Busse heat treat.

It's a good point that it would cost more. If it is in fact a different chemical composition (which I sadly couldn't verify through posts by BBusse higher
ups) it may be that they are requesting the higher end of the chromium scale for 52100 from the given manufacturer. It depends a lot on whether swamp
rat is buying pre-made stock from distributes or if they are buying the steel directly from the mill. If that's the case, they could be asking that they receive
stock with a specific limit on the carbon and chromium content, but still within the 52100 AISI designation.

http://www.matweb.com/search/datasheet.aspx?matguid=d0b0a51bff894778a97f5b72e7317d85&ckck=1

If they asked for 1.1% carbon and 1.6% chromium, 0% sulpher/phospherous, and .450% manganese They would technically still have 52100, but a very
particular version of it that has a higher chromium and carbon content than other 52100 blends. I'm weary of anywhere that says sr101 *is* or *is not*
something specific without being able to site a source for the information, like zknives listing it as "52100 VAC-ARC":
http://zknives.com/knives/steels/steelchart.php

It's equally possible that it's standard 52100, "52100 VAC-ARC", or a custom blend with even higher chromium or carbon than is called for in the standard
AISI composition. Without being able to site a specific reference of someone within the Bussekin management I can't say for sure that it is or isn't standard
52100. all I can say is that Cobalt's opinion was based on a knife maker veterans opinion, but I don't know if that was based on a spectral analysis or not.


"proprietary steel", as stated by eric, seems to imply that others could not get the steel itself, rather than the heat treat. They didn't change the name on
their 154cm or d2 stock, both of which got a proprietary heat treatment. If the impetus for the renaming of a steel was based on the heat treatment, I would
have expected them to change the name of all of their steels that it was applied to.

so, with a heavy sigh,

 

[Huntsman Knife Co. LLC.]

IMO SR 101 and SR 77 are the best carbon steels on the market at the price point. They are both incredible. Im not all that great at sharpening but both will take a hair splitting edge, SR 101 will hold that edge longer but i dont think any other company at the same price point can match what busse kin puts out. You'll be happy with any of the three steels and unless your an ace at sharpening you'll most likely not notice a difference in the level of sharpness you can achieve but SR 101 takes much longer to sharpen than SR 77.

 

[pioneertoo]

Ok, now I'm going to have some nightmares!

 

[whetrock]

Those were some eye opening photos it proves no knife is indestructable by the way my favorite busse-kin steel would probably be sr101 holds an edge like some kind of super steel but is tough like an old school carbon steel.

 

[DowntownDM]

remember, I tore a chunk out of the edge of my ASH chopping through that rusty chain...

Jerry wrote that it was due to lateral twisting as I was chopping, IIRC. In other words, had I held the knife straight and batoned through the chain it wouldn't have done that, but because I was swinging full force like a mad man, maybe 20 times, I was twisting it slightly some of the time.

I'll dig up the photos in a bit.

the chain:

the chunk:

a close-up:

and Jerry's comments:

Based on how the knife was used (loved), I would venture to guess that the missing piece of the edge was most likely damaged when it was wedged into a link and then torn out by the chain's movement during chopping! Had the chain link been stationary there might have been some dents but I doubt that there would have been any tears or rips in the edge. When steel chips, it almost always looks like chipped glass. If you look at the close-up pic of the edge, you can see where the steel was torn around the upper edge of what looks like the chip. This is typical of INFI under this type of impact on steel, where the steel continues to move after the edge is wedged in the steel. Whereas, most other knife steels would have chipped out dramatically along the entire edge, INFI simply dented and was ultimately torn out in just the one place. Very cool!!!

I held nothing back, and beat the f--- out of it against that chain. all in all I think the knife held up amazingly well, and, of course, Jerry and crew warrantied the knife even though I was monkeying around.

Gotta love it.