BUCK BLADE STEEL QUESTION

[gunom]

Hi, does anyone know why Buck changed from 425M to 420HC Thanks George God bless

[garddogg56]

George I'm pretty sure 1992.

[SteelMyHeart85420]

He asked why, not when....I can't answer it, though. Usually manufacturing decisions are cost based, it seems

[Old Hunter]

George, welcome back - I see you had to re-register. Here are some notes I have saved. The short answer is that Buck wanted to fine blank their blades and 425M was suitable and 440C wasn't; they started fineblanking with 425M and moved to 420HC a decade later. I also have other notes I cannot find right now from Joe Houser and Chuck Buck. I will try to find them as well. OH

The Blade Forum notes:

"I am unaware of any shortage of 440C. I would be shocked silly if there were ever a shortage of it. 440C is a standard AISI alloy and can be made by any steel manufacturer. Way too much usage for other non-cutlery applications for it to be in short supply. It's not like 154CM, which is an alloy specific to Crucible. If Crucible runs out of 154CM you will have to change alloys, if only to Hitachi's ATS-34.
When Buck used 440C they did not use fine blanking. They changed alloys several times and arrived at 420HC because they wanted to shift to a fine blanking process in order to reduce costs and improve production rates (OK so "reduce costs" and "improve production rates" are two sides of the same coin. Sue me.) Even 440A does not fine blank well.
Stainless steel requires a quench at negative temperatures (-115°F). This was discovered in Germany in 1939 and patented there. Henkel's Friodur process. Until that freeze quench became common, the properties of stainless were not suitable for good cutlery. Bernard Levine posted that he did not think the freeze quench became common in the US until the '60s. Until that time, the performance of stainless steel sucked little green toads. Once freeze quench became standardized, 440A et. al. worked about as well as carbon steel at holding an edge.
Any alloy which forms carbides (e. g. 440C or D2) is going to require a synthetic stone, (ceramic or diamond) if edges are going to be refined in a reasonable amount of time.
Frank R (knarfeng on Blade Forums).

Per David Martin, Buck Sub-Forum on Blade Forums - re: When did Buck begin using 425M; For the fixed blades it occurred in 1980 or 81. For the 110 & 112 it's at the 4 dot stamp. For all other models it's with the first year date stamp (1986)."

[Old Hunter]

Here are the notes I saved from C. J. Buck of Buck Knives.
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Originally Posted by CJ Buck (Blade Forums).
There are numerous threads on Buck's steel choices but I will summarize here...
My father pioneered 440C into production knives first as forgings and then conventionally blanked. 440C held a great edge but was prone to rust, pitting and breaking half moons out of the blades of users.
In 1981 we switched to 425M. It was a hard choice as our brand was built on the edge performance. The little we lost in edge performance we more than made up for in ductility and corrosion resistance. And we gained the ability to Fineblank which turned out very precise parts and better action in our folders then we had ever gotten.
420HC is a very close approximation of 425M and we get every ounce of performance out of it through our heat treating. You have got to remember that the steel you use, the balance of ductility and edge retention, is maxed out in Heat Treat. Folks out there have had bad experiences with 420J, a material popular with Asian knives, that does not perform even close to Our Paul Bos heat treated 420HC.
This started as a summary but turned into a soap box...and hopefully not too much of a commercial...
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Originally Posted by CJ Buck (Blade Forums)
User, yes we did change steels in 1980. Up until that time we had pioneered and used 440C as a replacement for file steel. My Father had felt that the 440C was rusting too much and wanted to know if we could get 58RC out of a steel that had less carbon. We switched to 425 Modified. It had a little over half the carbon that 440C did. This also allowed us to fineblank parts and helped with folder action with the accuracy in fineblanking.
In 94 we switched to 420HC. The HC stands for High Carbon, and is a relative term. Standard 420 is used for kitchen knives everywhere. The HC version is closer to the 425M and we get 57.5-58 RC consistently. Paul Bos has been a help there. This gives a nice mix of edge retention and corrosion resistance.
As to grinds...we totally changed our grinding in the 80's. We went from a semi hollow with a flat edging operation to a full hollow. It meant that there was not as much abuse resisting thickness along the edge but the new full hollow would cut better and hold an edge longer and be easier to resharpen.
In 2000 we redid this edge geometry again. Our testing said that edge geometry played a larger role in edge retention then blade material or hardness (when all things were fairly close). Edge geometry plays a huge role in resharpenability. Edge 2000, which we have now changed to Edge 2X keeps a very consistent edge thickness and a consistent edge grind thickness (bevel). We are looking for a bevel angle of 13-17 degrees on each side for an included angle of around 30 degrees.
One other point. The harder the steel the sharper you should be able to get your knife. When steel is sharpened to a fine edge it is very thin. Harder steels support themselves being thin better that softer steels so I have found that the knives we harden to 60 RC feel sharper to me. These edges being so fine also have a very high surface area to internal density ratio and many times edges are lost due to corrosion than use.
Sorry if I got a little long winded here.
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[garddogg56]

He asked why, not when....I can't answer it, though. Usually manufacturing decisions are cost based, it seems

S-O-R-R-Y

[Old Hunter]

Bad Dogg, bad Dogg - now you go sit in the corner! OH

[garddogg56]

I 'm in a round room OH called a missle cylo

[gunom]

Hi, Thanks very much, I think you covered everything, I knew people didn't like 425M much but I didn't know how much better 420HC is, I noticed that 425M would pit like 440C but I never knew it was a problem fineblanking, one thing for sure the 2000 edge is sharp, I wanted to have it put on a 420HC 560 the tech said that they only would say I will get a 13 to 15% edge, seems close enough, thanks again George God bless

[gunom]

Hi, I had to come back with my email I was using my wife's email but after about 10 try's to get back I just gave up and started over with gunom. George God bless

[gunom]

Hi, I had this from 1999 it's from Jeff Hubbard, Chuck Sr. wrote this, the dates seem wrong but it's worth a look . George God bless
Thread: Steel history of Buck


06-24-1999, 02:59 PM #1 Jeff Hubbard

My grandfather and father did make knives out of files up to 1961 when we incorporated. Grandpa Hoyt died in 1949 and my father continued making the knives using Lignum Vitae wood for the handles. In the 40’s he used Lucite and you know how that looks with the new Buck replica Hoyt Buck knife.

For the collectors, all of these wood handle and Lucite knives were made primarily out of files. Few were power hacksaw blades. You are correct that in 1961 we started using 440C, which is a very high-carbon, high chrome steel. I think the carbon is at 1.02 with a chrome of about 18%. It was an excellent steel but the carbides on the edge were very large and dulled reasonable quick. That is why we moved to the 425 modified (around 1985) so that the “homogenized” steel with the smaller carbides would not affect the edge so badly when they wore off the edge. (We went to 420hc in 1994)

True stainless is like tableware made with nickel and absolutely has no carbon whatsoever, and obviously would not hold an edge at all. This is not what we used. It was not a stainless, it was a rust-resistant material even today, of course.

You could tell when a knife was made and whether it was made of files. The files would be the ones with the wood and/or Lucite handles. We have made wooden handles and we are making them now, but these I think are a copy from the page out of our book that shows the different emblems next to the model numbers and would give him the actual year it was made. Any thing made from 1961 and forward is made out of a 400 series rust-resistant steel.


I hope this answers the question, let me know if we need more..

Jeff



------------------
Jeff "Without data it's just another opinion" Hubbard
Quality Supervisor


I think that anything we made from the post file era to approx 1985 would have been 440c. Then 425 mod, then 420HC.

Jeff

------------------
Jeff "Without data it's just another opinion" Hubbard

[gunom]

Hi, I had this from 1999 it's from Jeff Hubbard, Chuck Sr. wrote this, the dates seem wrong but it's worth a look . George God bless
Thread: Steel history of Buck


06-24-1999, 02:59 PM #1 Jeff Hubbard

My grandfather and father did make knives out of files up to 1961 when we incorporated. Grandpa Hoyt died in 1949 and my father continued making the knives using Lignum Vitae wood for the handles. In the 40’s he used Lucite and you know how that looks with the new Buck replica Hoyt Buck knife.

For the collectors, all of these wood handle and Lucite knives were made primarily out of files. Few were power hacksaw blades. You are correct that in 1961 we started using 440C, which is a very high-carbon, high chrome steel. I think the carbon is at 1.02 with a chrome of about 18%. It was an excellent steel but the carbides on the edge were very large and dulled reasonable quick. That is why we moved to the 425 modified (around 1985) so that the “homogenized” steel with the smaller carbides would not affect the edge so badly when they wore off the edge. (We went to 420hc in 1994)

True stainless is like tableware made with nickel and absolutely has no carbon whatsoever, and obviously would not hold an edge at all. This is not what we used. It was not a stainless, it was a rust-resistant material even today, of course.

You could tell when a knife was made and whether it was made of files. The files would be the ones with the wood and/or Lucite handles. We have made wooden handles and we are making them now, but these I think are a copy from the page out of our book that shows the different emblems next to the model numbers and would give him the actual year it was made. Any thing made from 1961 and forward is made out of a 400 series rust-resistant steel.


I hope this answers the question, let me know if we need more..

Jeff



------------------
Jeff "Without data it's just another opinion" Hubbard
Quality Supervisor


I think that anything we made from the post file era to approx 1985 would have been 440c. Then 425 mod, then 420HC.

Jeff

------------------
Jeff "Without data it's just another opinion" Hubbard