Guide to Tool Steel for Knife Makers

hey Walter Sorel's back with more tips for the knife maker today tool steels so what are tool steels and why should you care well let's start at the top tool steels are basically a category of hardened Abul steel so if you go down to Home Depot and there's a bin full of steel it says welding steel that steel I don't care what you do to it it will never get hard so try as you might you'll never be able to make a decent knife or cutting tool out of it I mean it's harder than a bag of chicken livers but it's not hard enough to do anything with that a knife maker tool maker would want to do so if you're a knife maker or even if you work in fabrication or machine shop or you know anything like that anybody that deals with steel really nice to know about tools deal so there's a general category of steels that contains over 0.5 percent carbon and generally a good bit more than that that can be heat treated and cooled in a way that makes them get quite hard so in the US these are designated with a letter followed by numbers so most of the some of the most common ones are w 1 a 2 D 2 and O 1 but there are tons of other ones you'll see S 5 s 7 H 13 M 2 now not all steels that are useful for knife making are designated as tool steels so why would a knife maker want to know specifically about tools deals well these are pretty commonly available steels you can get them from a lot of places and in fairly small quantities in ways that you can't necessarily with cutlery steels lots of industrial Supply places Stockham granger and some places like that so you know if you need something and you just want to run out and get it from a local store sometimes you can do that in a way that you can't with fanciers deals in these days the internet and one-click shopping and all that it's less necessary to know about then maybe it was 30 years ago but sometimes you just want to get something real quick and maybe there's a store down the way that you can run out to and get it and also save yourself the cost of shipping so the key to figuring out what kind of steel you want to use is to look at the attributes of the steel and see how it fits your application and the tools that you have these would include functional qualities like abrasion resistance corrosion resistance hardness shock resistance edge holding hot working qualities all that sort of thing as well as more process related qualities like the ease of heat treatment stability during heat treatment machine ability for mobility and so on in other words if a particular steel looks perfect but you don't have the gear to heat treat it correctly then it doesn't do your damn bit of good so you got to get something that is both gonna function like you want it to and that you're capable of heat treating now I'm gonna focus on knife making Steel's here but for those of you who might be working in machine shops fabrication or you know just guys who love tinkering in the garage I'm gonna mention a couple others along the way that might be more helpful to you than they would be to knife makers so tool steels are typically sold in the form of drill rod as well as in the form of flat stock if you're going to be forging you can just grab a piece of drill rod a big round piece of Steel you know heat it up and whack it into shape likewise if you're making a knife or maybe some kind of shop tool or a dye or fixture you can also find flat stock that's more useful for that when steel is produced at the mill there's generally a very thin skin of steel that has a lower carbon content than the specs for that steel would call for and that's not good typically they're not always tool steel unlike many other kinds of steel is sold with all of that decarburization ground off in that case it's usually sold so that it's slightly over the nominal size of the stock but it's also sold in what's known as precision ground form meaning that it's sold with the specifications of being within let's one thousandth of an inch to the nominal size what that means is that let's say it was sold as 0.25 Oh inches thick it'll be no smaller than 0.2 4 9 inches and no greater than 0.25 1 and that's just you know an example now for knife makers the downside is that you may not need all that precision why because precision is made out of money so if you're just gonna heat up steel and smash it with a hammer paying for all that extra precision may not make any sense but you know if you're gonna be making ten stock removal knives and you want to you know be able to assemble them maybe with interchangeable parts or you don't want to have to go out and grind a bunch of scale off of the the knife all that precision might be really handy so let's look at the most common steels available but first this so the most basic tool steel is called w1 it contains about one percent carbon a small fraction of a percent of manganese and the rest is iron now this makes it pretty similar to 1095 steel which is a really commonly available high carbon steel the main difference is that the specs for w1 or just a little bit tighter than for 1095 so if you see something in a catalog that's sold as quote-unquote water hardening tool steel and it doesn't say anything else it's almost always going to be w1 this means that it's relatively simple to heat treat you just heat it up to cherry-red dunk it in a bucket of water presto gets hard there's also sort of a kissing cousin w2 about the same composition but with a tiny amount of vanadium added which helps with wear resistance and it also has some kind of abstruse heat treating advantages now personally I prefer W to over w1 in all cases but unfortunately w2 is not widely available a lot of forging guys use it though but you have to kind of find it from specialty vendors in most cases so probably the most common tool steel is called oh one the oh is not a zero it's a it's the letter O and it stands for oil hardening it differs from w1 pretty much just in that has more manganese so without getting into the nuances of heat treating basically this means you can just heat it up to cherry red with a blowtorch or something you can dunk it in oil rather than water and it'll fully Harden so why would that be better than then water hardening well oil hardening is way less likely to cause parts to crack than if you quench in water water quenching is always kind of a roll of the dice things just crack and it's awful so as a result to me oh one is a much better starter steel for beginning knife makers except for one thing and that's expense if you're doing stock removal no problem definitely worth the trade-off but if you're forging on the other hand you kind of have to way whether that extra expense is worth the trouble I mean typically oh one costs like five or six times as much I'm talking about precision ground oh one here typically costs about five or six times as much as a piece of 1095 1080 something like that mil stock which still has scale on it and all that sort of thing next a two now a two is fairly similar to a one but with the addition of about five percent chromium now that chromium makes a big difference anything that is above about twelve percent give or take chromium is considered to be a stainless steel so that five percent chromium is not giving you a steel that's never going to rust so what's it there for well the a stands for air hardening chromium changes the heat treating characteristics of the steel substantially and it allows you to harden the steel by heating it up and then letting it cool in the air also chromium carbide are harder than plain old vanilla steel so by scattering these little blobs of chromium carbide through the steel you get better abrasion resistance it's used in tool rooms for fixtures dyes things like that if you want to make a quickie die for blanking or punching or something like that and you won't be doing gazillions of versions of it a two is a really handy steel to use but what about for knives well before we answer that let's look at d2 it's pretty similar in composition to a2 but with substantially more chromium and as we saw with a to chromium makes a big difference in in the case of d2 it's about 10 to 12 percent so that means that d2 is actually much more resistant to corrosion than a 2 so for tool and die and general shop use that may be a value may not but for knife guys the advantage is really obvious so as a result d2 is use way more than a 2 for knife making now it used to be that getting hold of cutlery steels like 440 C and that sort of thing in reasonably small batches was kind of difficult but now you know everything's available on the Internet I think a lot of fewer knife makers are kind of going right out of the gate to d2 and sticking with it for their career still excellent steel really makes very very nice knives you can make it quite hard without it being too brittle and it'll hold an edge for a long long time as far as corrosion resistance goes well I bought this Bob Dozier DT knife about 20 years ago and it's been sitting in a glove box in a variety of my cars including several abused by my son with water dripping in it and Georgia humidity and all that and look barely a scrap of rust take that for whatever it's worth now there are a lot of other tool steels out there most of them not so useful for knife making but for those of you who may not be interested in knife making or just want to expand your knowledge base a little bit let me talk about some of those other steels s-series steels S 5 and s 7 are probably the most common ones that you'd run into our shock resisting steels they have added molybdenum and silicon sometimes some other alloying elements that increase the toughness of the steel I've used some of these four swords and they're really not bad for that probably wouldn't use them for knives though all series also known as low alloy Steel's that's what the L stands for L six is probably the most commonly known one of those again very shock resistant and again not necessarily that great for knife making but can be good for for sword making Howard Clark for instance makes a japanese-style swords out of them kind of a special use thing though h-series steels are considered to be hot work steels meaning that they can be used at very high temperatures without losing their hardness h13 is a pretty commonly available grade of that they're useful mainly for injection molds and you know other kinds of industrial uses where things are gonna get really really hot unless you're planning to make a knife that's gonna be used on Venus not so useful for knife makers though kind of along the same lines where the m-series steels which also retain hardness at high temperatures they have a fair amount of tungsten and that makes them so that you can heat them up to very high temperatures and when they cool back down they'll retain essentially more or less their full hardness when you see things that are labeled HSS or referred to as high speed steel especially drill bits these are made from m-series steels typically pre hardened lathe tool blanks that you'll see sometimes in industrial supply catalogs again high speed steel typically an M series steel again if you're making lathe tools that's what you want not so great for knives because they tend to be more brittle than typically used knife making Steel's alright so one last kind of general point here you know I get people contacting me all the time he said well I got on these forums and I've looked around online and they're always people giving different advice about you know what kind of steel and how to heat treat it and whether this is useful for our knife or not and and I think you know a lot of times people they hear all this stuff and they just don't know where to start and they're kind of frozen in the water at a certain point you just got to jump into the pool and try something out you know buy a small quantity of something that seems like it might work for you chop off a little piece of it test out a heat treating technique and see if it gets hard you know you can stick it in a vise and whack it with a hammer and if it breaks then you know that it's hardened bear in mind you know I'm always talking about heating something to cherry red and dunking in a bucket of oil that kind of heat treatment is all very good and well but if you really want to optimize something for a particular use you want to sell your knives for a bunch of money or you're trying to make some kind of industrial part you really need to get your heat treatment dialed in and that may require more complex heat treating equipment higher level of knowledge that's just the way it is but don't let that stop you from just going out there and experimenting and trying something out and seeing if it'll make a good knife for you if you want to know more about these Steel's Google is your friend if you google oh one technical data sheet you know s7 technical data sheet whatever it is this will pop up now the manufacturer will tell you in a technical data sheet all about the composition of the steel recommended heat treatment all kinds of useful information if I were to make a really general statement and recognize that really general means not useful in some situations if you see chromium in a steel you probably want some kind of professional heat treating equipment to heat treat it on the other hand anything that says water hardening or oil hardening is something that you can heat treat reasonably effectively with reasonably simple heat treating equipment sometimes just a blowtorch and a bucket of oil simple summary like I said earlier all things being equal if you don't have a lot of experience and fancy equipment you can't lose by starting with oh one steel thanks for watching guys if you feel like you got something out of this video don't forget to subscribe also click on the link to patreon for a great way to give back to the channel plus check me out on Instagram Facebook Twitter links in the description if you want something sharp and pointy maybe a gift for yourself or one of the cooler people in your life check out my tactic armory website and pick up one of our tactical or outdoor knives and finally if you want to learn to make come-ons or Japanese swords check out Walther Sorrells blades comm where you can find videos about how I make home owned as well as forging mounting polishing and fittings for Japanese swords thanks and see you soon [Music]

Channel: Walter Sorrells

Views: 76,049

Rating: 4.9440765 out of 5

Keywords: steel, tool, 01, D2, A2, knife making, how to, maker, guide, introduction, information, help, explore, learn, forge, fire, Walter Sorrells, how to make knife, blade, folder, bowie, prepper, machinist, fabrication, welding, EDC, folding, metallurgy, machine, engineering, study

Id: mzSCxtHccFA

Length: 16min 21sec (981 seconds)

Published: Tue Sep 18 2018