Qualities of Bussekin steel

[J. Oeser]

Great posts LVC. Thanks for all the info!:thumbup:

 

[DowntownDM]

^^^ agreed, thanks LVC.

 

[Gator97]

Pardon, resurrecting this zombie, stumbled upon when researching steel subject. Still, I figure it's better to clarify why things are in steel chart as they are.

...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

1) Alloys in the steel chart are grouped by chemical composition, called reference groups. In addition, each group may contain alloy name which was listed by maker as an equivalent of a given alloy, in those cases note explicitly states that.
2) As for the source, back in the day when this page(http://www.swampratknifeworks.com/specs.html) still was active, it listed SR-101 as 52100 mod, plus numerous posts here on BF, especially back when it was first introduced, which is why it ended up in 52100 group. Also, the note on SR101 steel in the database clearly states "Busse Combat knives modification of AISI 52100 steel." If someone has more up to date information, I will be more than happy to update the database and properly credit the source, along with my sincere gratitude
3) SR101 is not listed "as 52100 VAC ARC". 52100 VAC-ARC, it is Latrobe version of AISI 52100, which doesn't mean it is the same steel as SR101, but simply lists a proprietary steel from Latrobe that is based on AISI 52100 standard spec, thus belonging in the same group(52100).

As things are today, all standard specs have variations, some very wild, e.g. W1 with 0.70-1.50 carbon, plus even individual makers specs for an alloy allow for variations, so unless you have a specific batch (or heat), it is not likely to get fixed values. Hence the grouping.

There is a really good book by John E. Bringas - "Handbook of Comparative World Steel Standards", much more knowledgeable in metallurgy and engineering than myself, where he says:
Comparing steel standards is not an exact science and there is no foolproof method. When you begin to use this book, you'll quickly discover that there is no such thing as "equivalent" steel standards.

Simply put, seeing two steels in the same group, doesn't mean they are identical. All it tells you, is that they are "similar" by their composition, or if the note states so, someone listed given steel as an equivalent of another alloy. Within the same group, whenever possible you have individual compositions, and when not, you get the note that alloy composition was approximated based on national standard or other alloys in the same group.
E.g the same 52100 VAC-ARC vs. AISI 52100 composition comparison. There are visible differences, but still within the specs. No reason to list them as different alloys. Also, often makers add extra element or two to the alloy, still listing it as certain standard, not to mention all the trace elements in the alloys.

 

[tundratrader]

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?

I would agree that SR77 is stronger and tougher overall than INFI. I have beat my dogfather to death and the edge will dull but it has zero chips or dings. My basic 11 has several decent chips and dings.

I agree that SR101 gets the sharpest and stays the sharpest. I dont have a M9 or any other big choppers to compare on that front. I have had similar sized 4-5 blades of all three and would say SR101 is best in that size.

For bang for your buck you cant beat SR101 knives. I think it will be interesting to see if the scrapyard 911 is SR101.

 

[Last Visible Canary]

I would agree that SR77 is stronger and tougher overall than INFI. I have beat my dogfather to death and the edge will dull but it has zero chips or dings. My basic 11 has several decent chips and dings.

I was actually saying that INFI is stronger and tougher than SR77.

What were the angles applied to each knife edge? Do you know if either knife was thicker directly behind the edge?
I ask because if both knives were tested/used with their factory edges then your using two different edges. Busse tends to put what I consider to be a fairly obtuse edge angle on their choppers, but not as obtuse as the dogfather and dumpstermutt I had. If you have one edge at 30 degree's per side and another at 40, I'd expect the one at 30 to suffer more dents, mashes and rolls because there's less supporting metal at the initial edge. If one knife is at .035" behind the edge and the other at .055" I'd expect the .035" to do worse for heavier damage because there's less supporting metal behind the edge. If both geometries are the same or roughly the same, I'd then look to what the knives came into contact with. If one was used in dirtier wood/environments that had more rocks/inclusions, I'd again expect that one to suffer more damage.

Do you have pics of what you believe to be chips in your B11? When you say the B11 has several chips and dings, is the edge still sharp otherwise?
I ask because I've only seen 2 images of what could be chips, but might be tear away chunks of metal. One of them is posted here. Either way, to the user the damage looks and acts (in use after the damage) like a chip. If your B11 has similar damage, I'd love to see it. Any user experience and especially photo's help build up a bracketing description of how INFI/SR101/SR77/the other heat treated steels from bussekin act under hard use.

If the B11 was still sharp where the dogfather was dulled, that indicates to me that the B11 is overall tougher since it resisted blunting across the work affected portion of the edge. If it was still sharp and both knives had similar geometries and edge angles, I would expect there to have been more hard elements in the media that dented the B11, and had they been present for the Dogfather similar dents, mashes and rolls would have occurred. If the dogfather had a more obtuse angle and was thicker behind the edge, I would expect that to be more of a factor in it's resisting deformation than it being a quality of the steel (if the B11 was still sharp overall).

 

[Last Visible Canary]

Still, I figure it's better to clarify why things are in steel chart as they are.


1) Alloys in the steel chart are grouped by chemical composition, called reference groups. In addition, each group may contain alloy name which was listed by maker as an equivalent of a given alloy, in those cases note explicitly states that.

Fair enough. When I read it, I thought it indicated that it was a different name for the same chemical makeup. I don't like the idea that if you take s7 and add an extra 2% chromium and call it sr77 that it would still be identified as the same steel. Though I do accept that the title given to a steel allows for significant variation in compositional percentages, I would hope that if the steel is sourced from a single manufacturer that the tolerances could be kept tight enough to be able to identify the steel (sr77) as being unique (and consistent) among the various manufacturers versions of s7.