Let's Talk About Steel

[Art]

Jeff,

I agree with D-2, it has been my go to steel for a long time, 1085 on the plain carbon side.  I like your selection of A-2 as a close runner-up, but then you most likely know how to work it.  Most folks here wouldn't have a clue how to handle it.  A-2 has taken air cooling to about it's furthest engineering form in the air hardening department.  I have two or three large blocks of it that I know the kids will put in my coffin.  If there is any steel that should be under coolant when it is NOT being worked, it's A-2.  "Even an apprentice should be able to drill a decent hole"; well, not in A-2.

Art

[bikermutt07]

 

Jeff,

I agree with D-2, it has been my go to steel for a long time, 1085 on the plain carbon side.  I like your selection of A-2 as a close runner-up, but then you most likely know how to work it.  Most folks here wouldn't have a clue how to handle it.  A-2 has taken air cooling to about it's furthest engineering form in the air hardening department.  I have two or three large blocks of it that I know the kids will put in my coffin.  If there is any steel that should be under coolant when it is NOT being worked, it's A-2.  "Even an apprentice should be able to drill a decent hole"; well, not in A-2.

Art

Art, how do these steels hold up to the liquid nitrogen treatment?

[Art]

 

Art, how do these steels hold up to the liquid nitrogen treatment?

The cryo treatment works well with most of the stainless or "almost stainless" steels.  This includes many of the alloys.  It is not a matter of "holding up", but more a matter of did your quenching process leave some retained austenite that you will "fix" (convert to martensite) with the cryo treatment.  Note, the cryo process should be done before tempering.  Cryo after tempering can leave untempered martensite which can be brittle; if there is a significant amount of it, stress cracks can cause failures.  I've always been a critic of the send us your (insert thingy here) and we will cryo it and it will be so much better, because they have no knowledge of the part's prior history, and the possibility of untempered martensite is a definite possibility.

Art

[bikermutt07]

Wow! That was some super elegant gibberish to my ears. I didn't have any idea what you were talking about, but I get your meaning. Thanks.

[Big Sioux Saddlery]

Well, I know next to nothing about metal, but I DO know what I like in a knife (or any tool) I'm going to use on a daily basis. So answer me this, and sorry if this is a really stupid simple question to you knife maker guys and completely off the subject, but I really want a logical explanation.  My favorite knives and tools are all OLD.  Some aren't all that hard to sharpen (and I'm not a sharpening expert either by any means) and may not hold an edge for all that long, but when those suckers are sharp, they are sharp, and have NO DRAG. And drag is one of my pet peeves. I pay a fair amount of money for a new edger or a new awl, or a new string bleeder, and no matter how sharp it looks or feels, and no matter how pretty they're polished, they have a DRAG that my old tools don't have.  I've got an old Rose knife that's a bitch to sharpen, but even semi-sharp, it doesn't drag like some of those newer kind-of expensive tools. I've got an old Gomph knife, and even dull, has less drag than an awl blade I paid way too much for. To be fair, I've never bought a new $250 knife, although one of these days I might, just because I like knives:-)  

[Art]

Older knives tend to be of thicker cross section.  These "thicker" knives are a little easier to get into a convex edge profile which guides them a little easier into the thick section which then holds the leather slightly apart as it approaches the cutting edge.  This reduces drag at the point where it is the greatest.  Even when a straight bevel is used, the thicker body of the knife acts to separate the cut pieces.  Remember that with a knife, there isn't much of a kerf.  Little if any leather is removed and the cut pieces will want to close up on the knife blade.  As you approach the edge of the knife, the cut pieces exert more grab on the blade and cause drag, so a thicker blade alleviates some of that to give a smoother cut.  On knives of a thinner cross section, you want the blade mirror polished to offer the least resistance, but for the smooth cut the cutting edge and about 1/32" to 1/16" back from it should be like a mirror with an 8000 or 3µ finish.  The included angle doesn't make a lot of difference (within reason of course), but a polished finish does.

Art

[MADMAX22]

I think regardless of thickness for leather cutting the edge should be  mirror or  near. I think leather has the ability to find any small roughness and take hold. One thing about the older knives they are probably all "high carbon" or some kind of low  alloy tool steel. They all tend to rust relatively easy but are easier to sharpen then say D2 which is a great knife steel but people give up on getting it sharp if they dont know any better. Ive "heard' or read about native americans complaining when traders started using the newer better steels as compared to the 1050 or such they would normally get because the tools they had to sharpen them with didnt work. 

I only have a few head knives, the CSO Newark which is pretty nice and the small gomph are the thinnest. The large gomph is thicker but tapers more, its about the same thickness as the rose blade. The D Martin is in the middle to thin side. All of these blades are pretty darn nice. Right now my go to are the small gomph and the large CSO which I primarily use for skivving. The little skinner is one I made out of 52100 a while back, got it a little too hard (about 64HRC) and it is a little chippy but it does a great job at cutting neoprene foam and other materials where I dont have to worry about hitting anything too hard. The rose being on the thicker side without as much taper as the others is great for thinner leathers but thicker stuff it pushes the leather apart to quickly which like Art was commenting on can be a good thing but also can fight against ya. The rose still holds a nice edge and is pretty easy to sharpen. I rehandled it with natural walnut and a piece of copper pipe. 

Sorry a little off topic but gotta  post pictures of your tools sometimes I guess. 

 

[Big Sioux Saddlery]

 

Older knives tend to be of thicker cross section.  These "thicker" knives are a little easier to get into a convex edge profile which guides them a little easier into the thick section which then holds the leather slightly apart as it approaches the cutting edge.  This reduces drag at the point where it is the greatest.  Even when a straight bevel is used, the thicker body of the knife acts to separate the cut pieces.  Remember that with a knife, there isn't much of a kerf.  Little if any leather is removed and the cut pieces will want to close up on the knife blade.  As you approach the edge of the knife, the cut pieces exert more grab on the blade and cause drag, so a thicker blade alleviates some of that to give a smoother cut.  On knives of a thinner cross section, you want the blade mirror polished to offer the least resistance, but for the smooth cut the cutting edge and about 1/32" to 1/16" back from it should be like a mirror with an 8000 or 3µ finish.  The included angle doesn't make a lot of difference (within reason of course), but a polished finish does.

Art

Thank you Art, that does make some sense, but doesn't explain the edgers, awls, and other tools. One night years ago I was sewing a cantle binding in the middle of the night. I was about half way through and I broke my awl (favorite one of course).  I didn't have another one even close to the same size. I dug around in my junk and found a great big old awl blade and ground it down, right there in the middle of the night. The blade looked terrible when I had it ground to about the size I thought it would work. I sharpened and polished it as best as I was able and went back to sewing. I was amazed at how well it worked. First chance I got, I ordered two brand new $25 awl blades that come highly recommended. I have never been more disappointed in a tool as I was in those new awl blades. Every once in awhile I dig them out and try them again, but I always go back to the ugly blade that I ground down in the middle of the night years ago. Only explanation I get from a guy I buy a few tools from is "They used better steel back then". Edgers are the same thing. I like my old ones. Maybe I'm just old:-)

[Art]

There might be something to the "better steel back then" theory.  Lets face it, steel for making knives, and steel for making tools in general constitutes a very small percentage of the market.  Steels that we can obtain today, especially tool steels, have all sorts of stuff in them for all sorts of reasons, almost none of it has anything to do with leatherworking tools.  Back in the day, the harness industry was huge and the tool industry to support it was correspondingly large and competitive.  The tool manufacturers ordered steel the way they wanted it as opposed to ordering what the steel industry provided them.  Do you think any of the leatherworking tools today are forged?  If so, they would be very expensive and it would be hard for them to compete in such a small market.  Too much trouble, bang out a bazillion of then in China, India, or Pakistan and drop them on the market at a better margin than a well made tool.  There are really darned few trades left, and leatherworking isn't one of them.  If a trade is big enough, toolmakers will produce a quality product for them, e.g. Klein, Irwin, Knipex, and maybe CSO.  Today, toolmakers produce for multiple disciplines if they want to stay in business, it just isn't the good old days anymore.

Art

[Big Sioux Saddlery]

 

There might be something to the "better steel back then" theory.  Lets face it, steel for making knives, and steel for making tools in general constitutes a very small percentage of the market.  Steels that we can obtain today, especially tool steels, have all sorts of stuff in them for all sorts of reasons, almost none of it has anything to do with leatherworking tools.  Back in the day, the harness industry was huge and the tool industry to support it was correspondingly large and competitive.  The tool manufacturers ordered steel the way they wanted it as opposed to ordering what the steel industry provided them.  Do you think any of the leatherworking tools today are forged?  If so, they would be very expensive and it would be hard for them to compete in such a small market.  Too much trouble, bang out a bazillion of then in China, India, or Pakistan and drop them on the market at a better margin than a well made tool.  There are really darned few trades left, and leatherworking isn't one of them.  If a trade is big enough, toolmakers will produce a quality product for them, e.g. Klein, Irwin, Knipex, and maybe CSO.  Today, toolmakers produce for multiple disciplines if they want to stay in business, it just isn't the good old days anymore.

Art

Now THAT makes a lot of sense!  And it sounds like buying leather. . . . the harness and saddlery trade makes up a very. very small percentage of all the leather sold worldwide, so we kind of have to take what we get, which is often what the other trades (Auto, upholstery, footwear, etc) don't want. I often think about what the harness and saddlery trade must have been like in the early 1900's, and think that would have been a good time to be alive. Now we're a long way from the original subject! Sorry and thank you!