Stainless Steel Classification SF 100

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Culpeper

Culpeper

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John Nowill & Sons out of Sheffield, England is manufacturing knives with SF 100 stainless steel. I never heard of it before. I do know that it is .67% carbon and 13.02% chromium. I think it is so-called "surgical grade" stainless steel but does anyone know what the American or other equivalent grade could be?
 
I don't know about that particular steel. I did have a cousin who made replacement body parts, Hips, knees,etc and the assorted pieces. He also made some surgical tools. He was telling me that with most of the stainless tools it is not as important to hold an edge as it was to be able to survive an autoclave with absolutely no rust. They are not cutting bone and if the instrument dulls they have more. Some fine cutters have small replaceable blades. Just because it would be great for surgery hardly makes it a good choice for our purposes. He gave me the steel types. I lost the paper. Most I had not heard of.
 
mete said:
That's similar to Sandvik 12C27.
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Okay, thanks...Sheffield is using it (SF100) for the Mariner Knife.

Grades
Sandvik 12C27




Sandvik 12C27 is a martensitic stainless chromium steel with an optimised analysis for high quality professional knives application. After heat treatment the composition of carbon and chromium gives a unique combination of properties including:
- Very high hardness
- Good corrosion resistance
- Very good wear resistance

This grade is also suitable for
- hunting and fishing knives
- pocket knives
- skate blades and ice drills
 
While they are all similar grades, that's slightly closer to 13C26, but that's just splitting hairs.
 
That is very close...


12C27 . C 0.6 Knives, scissors, skate blades
. . Cr 13,5 . .
.
13C26 . C 0.68 . Razor blades, scalpels, industry knives e.g. butcher band knives
. . Cr 13.0
 
A scaple blade is designed to make a couple of cuts and be thrown away.It doesn't need to hold an edge, just take a very sharp one and hold it for a moment. One thing you can be sure of, If it says Surgical Stainless, it isn't what we want in a hi quality knife. The .68c is very very low. Edge holding would be sub-par. Mike
 
Michael Lovett said:
A scaple blade is designed to make a couple of cuts and be thrown away.It doesn't need to hold an edge, just take a very sharp one and hold it for a moment. One thing you can be sure of, If it says Surgical Stainless, it isn't what we want in a hi quality knife. The .68c is very very low. Edge holding would be sub-par. Mike
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No it wouldn't.
 
I agree with Larrin. Don't underestimate Sheffield steel. Sheffield has been around a lot longer than Pittsburgh. SF100 is a proprietary grade that originated with Avesta Sheffield. It is being marketed in razor blade strips by Outokumpo but does not mean it is not suitable for knives. Especially, knives that are designed to be used around saltwater. The carbon in SF100 is no different than the 400 grade stainless made in America. I may stand corrected on this but I believe stainless steel was first developed in Sheffield.
 
Culpeper said:
I agree with Larrin. Don't underestimate Sheffield steel. Sheffield has been around a lot longer than Pittsburgh. SF100 is a proprietary grade that originated with Avesta Sheffield. It is being marketed in razor blade strips by Outokumpo but does not mean it is not suitable for knives. Especially, knives that are designed to be used around saltwater. The carbon in SF100 is no different than the 400 grade stainless made in America. I may stand corrected on this but I believe stainless steel was first developed in Sheffield.
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Stainless was first developed in Kokomo, Indiana.... At the same time, it was also being developed by someone in Germany, I believe.

Which 400 grade are you referring to?
 
Phillip Patton said:
Stainless was first developed in Kokomo, Indiana.... At the same time, it was also being developed by someone in Germany, I believe.

Which 400 grade are you referring to?
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Man, you got me researching now. I think, not sure, but Harrry Brearly invented stainless "rustless steel" in 1913. He worked in Sheffield.

I was referring to something like 440A. Though it has more Cr. 440A would be a choice over 440C if more corrosion resistant grade is needed. Like making a seaman knife. I can see why John Nowill et al is manufacturing their Mariner Knife in SF100 based on best available information since SF100 is proprietary grade and may have proprieties we are not aware of. Nonetheless, apparently it is inexpensive and suitable for saltwater use.
 
Culpeper said:
Man, you got me researching now. I think, not sure, but Harrry Brearly invented stainless "rustless steel" in 1913. He worked in Sheffield.

I was referring to something like 440A. Though it has more Cr. 440A would be a choice over 440C if more corrosion resistant grade is needed. Like making a seaman knife. I can see why John Nowill et al is manufacturing their Mariner Knife in SF100 based on best available information since SF100 is proprietary grade and may have proprieties we are not aware of. Nonetheless, apparently it is inexpensive and suitable for saltwater use.
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I checked out wikipedia's entry on stainless steel, but they made no reference to Kokomo IN. I know I read that somewhere though. I'll see if I can track it down. Not that it really matters, though...

I think 440c would hold a better edge than a stainless with .60 % carbon, but if stain resistance and toughness is more critical, then you may want to go with the lower carbon.
 
YW, Phillip. I hit on that tracking through googling "Stellite", which I always associate with Kokomo.
 
Phillip Patton said:
I checked out wikipedia's entry on stainless steel, but they made no reference to Kokomo IN. I know I read that somewhere though. I'll see if I can track it down. Not that it really matters, though...

I think 440c would hold a better edge than a stainless with .60 % carbon, but if stain resistance and toughness is more critical, then you may want to go with the lower carbon.
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440C is indeed more wear resistant, but I don't agree that it will hold an edge better, simply because the 13C26 can be taken harder with greater toughness. Hardness will win out here, IMO, though things could possibly equal out depending on the test done. 13C26 is more wear resistant than any of the common forging alloys (1095, 52100, O1, etc.) and no one complains about the wear resistance of those alloys. I don't think there would be a significant difference between the stain resistance. AEB-L, which 13C26 copied, was developed in the early 1900s.
 
Larrin said:
440C is indeed more wear resistant, but I don't agree that it will hold an edge better, simply because the 13C26 can be taken harder with greater toughness. Hardness will win out here, IMO, though things could possibly equal out depending on the test done. 13C26 is more wear resistant than any of the common forging alloys (1095, 52100, O1, etc.) and no one complains about the wear resistance of those alloys. I don't think there would be a significant difference between the stain resistance. AEB-L, which 13C26 copied, was developed in the early 1900s.
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There's more to wear resistance than Rockwell hardness alone. 440c, because of the higher carbon content, would have more carbide volume than 440a.
Can you point to some hard data that shows that 13C26 is more wear resistant than O1? I really don't know anything about 13C26, so I can't really argue against it....
 
Learn something new everyday. Well, we got two guys, both leaders in their fields, discovering stainless steel about the same time...

It is reported that the first true stainless steel, a 0.24wt% C, 12.8wt% Cr ferrous alloy, was produced by Brearley in an electric furnace on August 13, 1913
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http://en.wikipedia.org/wiki/Harry_Brearley

Haynes received patents on two alloys: stainless steel and stellite. He founded the Haynes Stellite Company in 1912 Kokomo, Indiana[1] which was bought by Union Carbide in 1920
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http://en.wikipedia.org/wiki/Elwood_Haynes

What knives do we normally see made of 440A. I've assumed kitchen cutlery and so forth. Especially, home kitchen cutlery because they have to stand up to dishwasher abuse.

BTW, stay away from Frost Cutlery products. I've seen their Hen&Rooster so-called 440A made in China steak knives rust up the edges the first few times in a dishwasher. They can't be real 440A they are using. That stuff is just plain junk. I'm getting sick and tired of all this Chinese crap floating around. On the other hand, I have some inexpensive Victorinox kitchen knives that have been holding up very well.

But back on Sheffield and stainless steel. I've just recently purchased a knife set on the cheap that is Sheffield stainless. These were made in the 1960s. Of course, I'm going to run them through the dishwasher and see how they hold up.

Kershaw is one knife producer that uses 13C26. I'm sure there a lot more out there.

http://www.knivesunlimited.com/folding-knives/everyday-knives/kershawkostormiik1475st.cfm#navbar=a
 
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