CASE HARDENING Carburizing vise jaws #717 pt 1 KASINIT tubalcain

howdy again it's mr pete and by popular demand i'm going to present this two part video on case hardening also called surface hardening or carburizing and there's just an awful lot of related information and that's why the video is going to be so long now i do have the furnace preheating here it's been on for about 90 minutes already and it just takes about two hours to get up to 1650 or 1700 degrees which reminds me that 50 years ago i'd have to get to the high school at six in the morning in order to turn the furnace on and get it heated up by first period if we were to do heat treating that day and you know i wasn't the only one that had to get there early i noticed that there were teachers up on the third floor english teachers that already were cramming for the day uh boning up on emily dickinson and t s eliot and walt whitman and so on and some of the bathroom teachers were there too boning up on euclidean geometry not the furnace is warming up it's about 1400 or 1450 still has little ways to go and boy that heat feels good on a cold morning like today so what equipment do you need for case hardening well you need a heat treating furnace or an oxyacetylene torch and you can do small parts just hanging from a wire without the use of a furnace but for larger pieces this really is your best bet but not everybody is going to have that i know that this came from a dentist's office i've had this for about five years this would be a rather expensive furnace it is 15 amps so it will plug in at 110 and it can be preset which i already have for 16.50 now i'm getting ahead of myself here you'll also need your various safety items glasses shields gloves and so on and a bucket of clean water that's a galvanized bucket don't use plastic and you notice that it leaks i have a fire brick here this is what we're going to do of course these little swivel jaws which there's a five part video on that it might help to have a little baker's pan like this to put some of the carburizing material in and then most important you will need some surface hardening compound now i am sorry to tell you that this case night is no longer available i've had this for several years already but it's probably a 50 year old container that came from maxwell street in chicago and i bought this from my friends in a little town and there was a video on that i'll put it on the screen now that was uh all about getting rid of uh oh i forgot the name of the title here's the title watch this video a lot of people have watch this two-part video of mine sometimes called the disassembling of american industry it's a two-parter from may i'm sure you will enjoy it now i'm going to put pictures of these definitions of case hardening at the end of the video so you can read them and study them but this information is available in virtually every metal working book but case hardening and this is from the text by fire john l case harding is a process of hardening the outer surface or case of ferrous metals by adding a small amount of carbon to the case of the low carbon steels it can be heat treated to make the case hard at the same time the center or the core remains soft and ductile and read through the rest of it very interesting okay this definition is from the henry ford shop theory book of which they printed 10 million copies perhaps you have one but in here they even suggest that you make your own carburizing compound out of charcoal and all of these references refer to about 1650 or 1700 degrees which is very very hot cherry red i took the liberty of putting on paper the description and directions here on the back of the casonite can it's a little hard to read here now i've been told that casonite is a coke type of carbon product so here are the directions off of the casinite can this was a widely used product in almost all school metal shops no longer available as i said and we are always case hardening mild steel that's what it's all about not tool steel although although it does talk about using it on tool steel on the directions but i didn't print those out but for mild steel heat the part uniformly to a bright red temperature of about 1650 then dip or roll in a compound to form a fused shell around the area to be hardened reheat to a bright red quench immediately in clean cold water using a scrubbing action to ensure maximum cooling rate that means a figure eight and then to increase the depth repeat the operation notice the warning on the can says casonite compounds are highly refined non-poisonous non-flammable and non-explosive so they were safe to use in schools this is a five pound can of case tonight it was almost full it was so rusty on the top i had a heck of a time opening because it had never been opened so uh and this is the number one i don't know if there was a number two or a number three i never heard of them but this is what i'm going to be using but since this is not available anymore let me show you two or three other sources of a similar compound this seems to be the most popular surface hardening compound now it's called cherry red here it is and these are terrible pictures taken off the screen this is from travers and it's thirty dollars for one pound and then you add the shipping there you got almost forty dollars for one pound which isn't very much and here is a description of that product still pictures available at the end of this video mcmaster carr has their own brand available in various sizes one pound is 25 over 25 but you can buy a five gallon pail of it if you have an ocean gunsmiths do a lot of case hardening on small parts here it is in the brownells catalog also what twenty seven dollars for a one pound container so check that out probably all of the gunsmithing catalogs offer this product do not confuse what i am doing with the beautiful color case hardening that they did many years ago and you can still see it on antique firearms and tools i was looking around here and the only tools i have that were color case hardened it has worn off so i don't have a good example to show you but that was done by a cyanide process that was incredibly dangerous and toxic it was no longer done anymore you know cyanide was a good uh and arsenic were good uh rat killers and it killed humans too and i think cause all kinds of uh physical problems so don't mess around with arsenic but i should say uh cyanide but you're not gonna find it anyway it isn't available i don't think any place so anyway this is not color case hardening i know i'm jabbering a lot but there's just a terribly large body here of information that i wanted to cover if you're a metal worker you are familiar with this color chart and this was put out by temple many years ago it was printed in virtually every textbook also i had better copies on the wall at school so often you'll see this picture around a heat training area in a factory see this was just torn out of one of the textbooks that i have let's talk about it now the dark part here is the steel at a lower temperature where it's just a natural color but as you start getting here and these are the temperatures on the far left all in fair fahrenheit sorry for you guys in europe but at about a thousand degrees that's where the very dull red starts appearing and then it becomes brighter and brighter until it gets to be cherry red by the way all of this information is in metallurgy textbooks but you do not want to read those because they turn into a chemistry class and it's impossible to understand unless you are really well adversed in math and science and all that but all right here's a thousand degrees and we get hotter and hotter then we get into the carburizing range and you can see that's between 1700 and 1800 and that's the temperature we want now you're not going to have a thermometer on your furnace probably so you can go by color it's quite accurate cherry red and the critical temperature i believe here at 1400 degrees is what we call the magnetic point and if you check a piece of red hot steel at that temperature or above you will find and touch it with your magnet you will find that the magnetism there is no attraction at that point very unique i think i like to show that to the kids at school but of course as it cools that magnetism reappears that's all i'm going to say about this chart it's very very interesting one more thing one more thing now i just showed you the carburizing area so number 11 and it was numbered 11 and then you can read it there that carburizing consists of dissolving carbon into surface of steel by heating to above the transformation stage in presence of carburizing compounds how about that okay i wanted to show you a few things out of the old ryerson stock list and this is a 50 year old book but it doesn't matter none of this has changed but the steel that we're going to case harden is low carbon that is 10 18 steel and notice that here in the index they even call the rounds here low carbon case hardening type of steel medium carbon is called direct hardening and this page shows the chemical composition of steel and the ruler is right on 10 18 and the carbon content is from point 15 to point 20. so point 18 is probably about average and that's where they get i believe the number 1018 steel here's a sample piece that i carburized yesterday notice that it changes the color but it isn't objectionable at all and can you tell by the sound i'm not sure if that picks up or not that it is hard now how deep is the case hardening on this piece i don't know there's no way of me in i have no laboratory of checking that but it's probably only one two three four thousandths and the longer you soak it in the carburetion compound the deeper the case will be now i did this actually by two methods yesterday two different samples the first one i put in the furnace and brought it up to 1650 took it out glowing red hot and put it in this little pan of casonite i rolled it around let it in there a few minutes and i really thought that it would get a thicker crusty layer stuck to it it did not it was rather scant then i put it back in the furnace and let it in there all half hour i think it was and took it out and quenched it remember there's two different things here one is you're carburizing it that is you're adding the carbon and then once the carbon has been added you have to go back and heat treat it that is harden it but you will not have to temper it as we do with tool steel now here's the second method that i tried i made this little tray this morning out of 20 gauge steel it was painted so i i had to burn the paint off i went outside to do that so that my long suffering wife didn't have to smell that throughout the house and even what i'm doing here will smell a little bit but i'm going to do it by two methods again and in this tray i will put some of the compound and then when it's red hot i'll place that on the compound and sprinkle more on the top and then put the little tray into the furnace i think i'm going to go for a whole hour on that then take it out and quench it and it will be hardened this is the tray that i used yesterday and whatever was left in there is not reusable as you can see some of it did stick to the part and it came off of course when i quenched it and of course the sheet metal is more or less consumable the temperature is now 1600 degrees so it won't be too long before we get to hardening here i took a fire brick which i bought at tractor supply and cut it in half which was no easy job i had to drill holes but why am i telling you that well the other half is in the furnace and that is my hearth so to speak because this does contaminate my furnace and i do value this furnace and it would be very very expensive to buy one the one i had at the high school was really quite a bit smaller and you had to guess at the temperature and yes of course these jaws would be far better if they were made of tool steel and could be hardened throughout probably all vice jaws on bench vices or quality devices are hardened by that means with tool seal you know tool steel is pretty expensive considering you'd have to buy a bar of it so you you know you might have 40 or 50 dollars in tool steel alone and most of you do not have the budget for that as i do not myself now if enough people watch this video if there's enough interest in heat treating and again i'm not a metallurgist but i think i would go ahead and make more videos one on hardening and tempering of tool steel and one on annealing although you've seen me anneal and i don't mean kneeling i said unknell also an interesting process then there's normalizing you know there's all kinds of different processes this is fascinating work if you're a metal worker a machinist so the furnace is just about there and again what i'm going to do now and i have a piece in there now soaking now soaking means you leave it in there long enough so it is the same temperature throughout no matter how thick it is even if you were in the center of this piece it would be 1700 degrees in the center the same as it is on the outside now that takes a while to to to get to that degree of hotness heat or whatever you want to call it and that's why we call it soaking takes a while but the first i already have one of these samples in the furnace as i said i'm going to bring it out here in the next scene which might be a half hour from now but it will be instant for you and i'm going to put it in the pan of case night and cover it let it sit in there for a few minutes and then put it back into the furnace are you ready for that finally about time you're thinking the temperature is 16.50 so let's take a look holy mackerel is that hot so i dropped it in the pan and i want to cover it now can you see that now i'm going to leave it in there for just a couple minutes as you can see it smokes a little bit but not too bad then i'm going to shake it off we'll see how much the shell builds up but i do not expect it to be a lot now remember i'm still doing uh a sample rather than the jaws themselves and there's a slight ammonia smell to this some furnaces have a little peephole in them so you can see what the temperature looks like as far as the color but i guess because of the fact that we got the thermometer on here they they passed on that but when you open this to take your work in or put it in or take it out make it fast you do not want to lose any of that heat because it's going to take five or ten minutes to make that up even if you got it open almost momentarily okay it's been five or ten minutes i'm going to take it out put it into the furnace see most of it falls off that might have been a little bit too much of a crust i don't know remember i'm experimenting too and in 30 minutes i'll open it up but boy this is smoking like crazy all right it's been exactly a half hour since i put this in the furnace put your glasses on figure eight now there's a bit of a scale on it so let me clean that up with a wire brush but i think it's a good one there it is it looks pretty nice i kind of like the mottled color now some people pack it and make it uh air tight and so on and do this for a whole day but using a file my only way of checking it it does feel quite hard how deep the case is again i will never know okay that concludes part one of this very long video and i've just done the samples of the vise jaws in the next part part two i will do the actual swivel jaws themselves and i hope you join me for that thanks for watching you

Channel: mrpete222

Views: 53,174

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Id: ttXZ0vtAHFI

Length: 22min 43sec (1363 seconds)

Published: Sat Apr 17 2021