ok I've seen all kinds of steel discussed here but I see a lot of knives turned out of 420, 410, 440 stainless, AU8, cryo tempered(?) could ya run a quick easy to understand essay how all these are different for a poor ignerent woods runner :wink: are any of them decent steel for a blade? most all cutting stuff I have n use is old carbon steel, curious. thanks guys
hey all you metal guys
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I'll try. Only the 440 series of the 400 series of stainless is worthy of a knife blade. Only 440-C makes a good one. If cryo tempered makes a very good one, despite what you hear about stainless. 440-A works, but the edge doesn't last very long, 440-B is better and used to be popular for dive knives due to it's superior rust resistance. ATS-34 and 154 CM, are another stainless type that beats the 440-C. Cryo is of course a deep freeze. If I recall correctly, not very effective until below -100°F. The best cryo treatments are done with liquid nitrogen. When any high carbon steel is hardened, the object obviously is to convert the soft condition into the hard condition. The hardened steel condition is called martensite, and the soft highly heated version that has formed an homogeneous solution of iron, carbon, and alloys, austenite. When quenched, there is always a little austenite that does not convert to martensite. Tiny fragments of the austenite solution, stay in solution when cooled, but do not convert. The cryo treatment forces more of the retained austenite to convert to martensite, thus producing a yet harder and stronger steel. Though it has to be tempered afterwards to not be brittle. This treatment only works to real advantage with the high alloy types of steel. For common iron/carbon steel there is not enough return for cryo to be worth while. I know nothing about AU8.
There all different in make up. Some good some not so.The 440 has some variation's 440, 440A,440B,and 440C the 440C is the one to use the others arent real good. You can google each type you want to study and learn the different % of the materials that make that up. I believe Cold steel use's 420, 154CM is suppose to be real good Ive not messed with any so I cant tell you as far as making from scratch how well it works I will tell you that i have modern knives that have good quality stainless blades that work great. Not sure if they will let this topic up since it isn't period correct Im sure Wick will be on here then and shed some more light on it
thanks guys, I know all the different numbers mean different things with different metals but like I said I'm totally in the dark in knowing one from the other. Was looking at a catalog yesterday n noticed all the different numbers n thought this would be the best place to ask. I'll try googleing it up, never even thought something like that might be there but heck everything else is LOL again thanks , that really clears the clouds away for now.
The 400 series are what is referred to as martensitic, that is, they form martensite at room temperature after quench. The 300 series, another commonly encountered series, do not form martensite, and are not used in edged tools.
AUS8 is another martensitic grade which has the highest carbon content of the AUS series. AUS6 and 8 are the grades most commonly found in cutlery.
Cryogenic treatment is a process in which the blade, after quenching to room temp, is immersed in a liquid nitrogen bath, often to as low as -300F. This allows for the complete transformation of austenite to martensite in the steel. This process is also used in the manufacture of some rifle barrels. In quenching, not all of the austenite is initially converted to martensite. The blade's structures are unstable and may either remain austenitic, or convert to martensite.
My guru, Karl Schroen, refers to this phase as "unstable austenite". He claims that as much as 30% of the structures, by weight, are unstable.
In your more highly alloyed carbon steels, like A2 or CruWear, two tempering cycles are used. In your stainless steels, which are typically even more highly alloyed, a double-quench, followed by a double temper, is used. In industrial settings, a cryogenic treatment is used.
I still prefer a carbon steel for most uses, as they can be sharpened more readily than most stainless, esp. the high vanadium alloys. I usually suggest stainless to my customers that are mariners or cook who cant be bothered to care for their knives.
My favorite steel for replica knives is O-1....really easy to forge and heat treat and takes a superb edge. A2 performs better, but is MUCH more expensive. O1 is the best value.
AUS8 is another martensitic grade which has the highest carbon content of the AUS series. AUS6 and 8 are the grades most commonly found in cutlery.
Cryogenic treatment is a process in which the blade, after quenching to room temp, is immersed in a liquid nitrogen bath, often to as low as -300F. This allows for the complete transformation of austenite to martensite in the steel. This process is also used in the manufacture of some rifle barrels. In quenching, not all of the austenite is initially converted to martensite. The blade's structures are unstable and may either remain austenitic, or convert to martensite.
My guru, Karl Schroen, refers to this phase as "unstable austenite". He claims that as much as 30% of the structures, by weight, are unstable.
In your more highly alloyed carbon steels, like A2 or CruWear, two tempering cycles are used. In your stainless steels, which are typically even more highly alloyed, a double-quench, followed by a double temper, is used. In industrial settings, a cryogenic treatment is used.
I still prefer a carbon steel for most uses, as they can be sharpened more readily than most stainless, esp. the high vanadium alloys. I usually suggest stainless to my customers that are mariners or cook who cant be bothered to care for their knives.
My favorite steel for replica knives is O-1....really easy to forge and heat treat and takes a superb edge. A2 performs better, but is MUCH more expensive. O1 is the best value.
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Just so that a beginner might know, 01 is a relatively easy heat treat, BUT, ONLY if you have the means to perform a controlled temp heat soak before quenching, and have an oil to match it's needs. It is NOT a good beginners steel, and does not do well with simple back yard heat treats.
LOL I'll leave the real knife maken to you guys who know what the heck you're doing and are so dang good at it. I'm just trying to get a better idea of what I'm seeing n reading with the descriptions of knives, swords n such. I'll rehandle old butchers n the like maybe reshape a bit but forgen I leave to the pros. You guys have an amazing talent to turn an ugly hunk a steel and some antler into the most beautiful works of art. :bow: every day ya learn something new is a good day
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Pretty good run down, nothing to really add. Just a couple notes on stainless.
Generally speeking, everything is a trade off, to get corrosion resistance, you generally give up some toughness and edge holding. ATS-34 and 154CM are tougher and hold an edge longer than 440C, but aren't as corrosion resistant.
CPM steels have the best of both worlds, fine grain structure and good toughness and edge holding, but there steels cost more, and are still not as good in the toughness department as carbon steels. What tends to make most stainless not hold an edge as well and not be as tough as carbon steels is the same thing that makes it stainless, the chromium in the alloy. A little bit can refine grain structure, like in O-1, 5160 and 52100. But enough to make the steel stainless makes for large grains, which make for weaker blades. The more chromium past a certain point, the more rust resistant, but the weaker the blade. In general, there is more to it than that, but that's the general idea.
All that said, the steel doesn't mater, it's the heat treat that makes a blade. The highest performance steel out there with a poor heat treat will be out performed by simple iron and carbon steel with an excellent heat treat.
Generally speeking, everything is a trade off, to get corrosion resistance, you generally give up some toughness and edge holding. ATS-34 and 154CM are tougher and hold an edge longer than 440C, but aren't as corrosion resistant.
CPM steels have the best of both worlds, fine grain structure and good toughness and edge holding, but there steels cost more, and are still not as good in the toughness department as carbon steels. What tends to make most stainless not hold an edge as well and not be as tough as carbon steels is the same thing that makes it stainless, the chromium in the alloy. A little bit can refine grain structure, like in O-1, 5160 and 52100. But enough to make the steel stainless makes for large grains, which make for weaker blades. The more chromium past a certain point, the more rust resistant, but the weaker the blade. In general, there is more to it than that, but that's the general idea.
All that said, the steel doesn't mater, it's the heat treat that makes a blade. The highest performance steel out there with a poor heat treat will be out performed by simple iron and carbon steel with an excellent heat treat.
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I totally agree! In the eighties I worked 440-C, and ATS-34. Heat treat was by Paul Bos. The edge cutting performance was super, but prone to chip out a tad bit if misused. 01, IMO, matches the cutting ability of either of those, if not excells, with better toughness.
ok guys looking to learn a little here, if you were going to buy a sword, one called battle ready, that you could actually really use as a sword, what type of steel would you prefer and maybe a second choice as well, and why.This whole discussion may not be completely PC/HC but there is mention of swords being carried so I guess we can stretch things a bit, this is facinateing--n thanks YMHS Birdman LOL Wick this is all yer fault ya know, posting that pretty piece like ya did. :blah:
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If I had my preference it'd be made of either 5160, a supper tough steel when heat treated rite, or maybe a Howard Clark L-6 with Bainite back and martensitic edge.
Since my experience with L-6 is limited, though it's a tough steel, I'd have to go with 5160 with differential heat treat from experience. 5160 is a little lower down on edge holding from some of the other sword steels, but done rite it's virtually unbreakable, and in life or death that's more important than a notched edge.
Another candidate is one of the shock steels, like S-7, but I have zero experience working it.
I would add that there is no way, no how I would ever want a stainless sword blade that did more than hang on a wall. Stainless has it's place and I use it, but even the CPM steels don't compare with carbon steels for shock resistance.
I would add that from my cutting test O-1 has 440C beat by a pretty good margin, and ATS-34/154CM(which are the same steel, just two different countries make it) by a smaller margin, but is easier to sharpen and holds a finer edge than either. My personal favorite for a knife is 52100, but it's time consuming to get the best performance out of it.
Alloys do funny things sometimes, just looking at the alloys of O-1 and 52100, there very similar and by rites O-1 should slightly outperform 52100, but I get another 20% of cutting from 52100.
Since my experience with L-6 is limited, though it's a tough steel, I'd have to go with 5160 with differential heat treat from experience. 5160 is a little lower down on edge holding from some of the other sword steels, but done rite it's virtually unbreakable, and in life or death that's more important than a notched edge.
Another candidate is one of the shock steels, like S-7, but I have zero experience working it.
I would add that there is no way, no how I would ever want a stainless sword blade that did more than hang on a wall. Stainless has it's place and I use it, but even the CPM steels don't compare with carbon steels for shock resistance.
I would add that from my cutting test O-1 has 440C beat by a pretty good margin, and ATS-34/154CM(which are the same steel, just two different countries make it) by a smaller margin, but is easier to sharpen and holds a finer edge than either. My personal favorite for a knife is 52100, but it's time consuming to get the best performance out of it.
Alloys do funny things sometimes, just looking at the alloys of O-1 and 52100, there very similar and by rites O-1 should slightly outperform 52100, but I get another 20% of cutting from 52100.
Ha! I have never seen a steel that does well with the usual "backyard heat-treat" (gee..dump it in the fire until its ...uh...kinda orange...and then quench in "tap water")
I have successfully used O1 for my intro blade smithing class for years and gotten very good results. Yes, the heat treat is done very carefully, using quenching oil specifically formulated for cooling rate.
O1 is a simpler steel to work with than say..A2...which is simpler that ATS34. The higher the refractory element count, the less forgiving the steel is of careless forging or heat treat.
Any aspiring bladesmith should do a few knives under qualified supervision before "winging it" in the backyard forge. Primitive forging conditions require the most knowledge of materials and forging concepts/environments, not less.
I have successfully used O1 for my intro blade smithing class for years and gotten very good results. Yes, the heat treat is done very carefully, using quenching oil specifically formulated for cooling rate.
O1 is a simpler steel to work with than say..A2...which is simpler that ATS34. The higher the refractory element count, the less forgiving the steel is of careless forging or heat treat.
Any aspiring bladesmith should do a few knives under qualified supervision before "winging it" in the backyard forge. Primitive forging conditions require the most knowledge of materials and forging concepts/environments, not less.
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On the flip side, if you were interested in making HC / PC blades, what steel comes close and what quenches were common back in the day? 1095? And a skillfully executed brine quench?
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Without making your own blister, or shear steel, more like 1070/75. I would quench in a fast oil.
Yep, The steel today isn't the same stuff they used at the time. The other thing is that some steel is air quench and others oil, I think W-2 (?) is water quench. I've done some files that were okay ( that is- not great- just okay)- if you just want to fool around files will work. I can make springs that work well.
