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As I understand it, "normalizing" is a process where you kind of reset the grain of the metal, eliminating stresses that you may have created by working it. It's important when doing knifemaking because if you've smithed your blade and then don't normalize it before doing your hardening quench, you may find it twists or bends in the quench. Normalizing hopefully prevents that. If you happen to anneal somewhat while normalizing then you've lowered the hardness (of a steel that is hardenable: this does nothing to mild steel) but it's not necessarily the case that normalizing is also annealing. Using an oven gives you maximum control over the rate of cooling. A box with an insulator or even just burying it with some sand will get you "close enough" for typical carbon steels.
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Dec 23, 2012 05:25
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Cuprous alloys working the other way 'round is really, really convenient. Quench turns everything butter-soft and cool and ready to work again in seconds- but if you wanna temper it without forging and work-hardening, you can do that too, if you have an oven or kiln. e: Why -is- it the other way around with copper and the like, anyways? What physical property on the molecular level makes one metal respond to slow or fast heating in a way that is the polar opposite of another?
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Dec 23, 2012 06:43
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Ambrose Burnside posted:Cuprous alloys working the other way 'round is really, really convenient. Quench turns everything butter-soft and cool and ready to work again in seconds- but if you wanna temper it without forging and work-hardening, you can do that too, if you have an oven or kiln. I think it's because iron is a body centric cubic molecule, and copper is face centric. http://en.wikipedia.org/wiki/Cubic_crystal_system It's a property of body centrics crystalline structures to harden when you deform them. I think. My understanding of this is pretty basic, and possibly wrong. Also it's too late to do as much reading as the subject demands tonight.
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Dec 23, 2012 07:48
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My very basic understanding of iron is that once you pass the critical temperature it switches from body centric to face centric, and there's then enough room between the iron atoms to accommodate carbon atoms. When cooled quickly, as in quenching, the crystals switch back to body centric so fast that carbon is trapped inside the crystals. Hence how hard and brittle it becomes. Copper I'm less familiar with.
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Dec 23, 2012 08:07
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 INCOMING STEEL SPERGOkay, when you start with pure iron and begin to heat it, it is in its BCC phase, this beginning phase is called ferrite, or α-iron. At 912°c this ferrite turns into austenite, or γ-iron which persists to 1394°c, this is Face centered cubic. At 1394°c the austenite turns into δ-ferrite, which is BCC again, then finally melts at 1538°c. The FCC phase is used to introduce carbon into the system, and then you start playing with a new structure called Fe3C, or Cementite, and now you have entered the wonderful world of steel and there are 4 new regions on the 0-6.7% phase diagram. What terminal saint is referring to above is the change from γ+Fe3C to Martensite, which has a Body Centered Tetragonal crystallography. The change is indeed achieved through rapid quenching of γ+Fe3C and the Martensite forms in little spears inside the greater structure of the Austenitic steel. Info courtesy of Fundamentals of Materials Science and Engineering: An Integrated Approach, 4th Ed. Callister & Rethwisch. Samuel L. Hacksaw fucked around with this message at 16:58 on Dec 23, 2012 |
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Dec 23, 2012 16:27
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Leperflesh posted:I'm not sure this is an effective anneal. Keystock and really anything that needs a good case hardening is often an 86XX alloy. Gears, hard trans parts, etc.
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Dec 23, 2012 18:32
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Lord Gaga posted:Keystock and really anything that needs a good case hardening is often an 86XX alloy. Gears, hard trans parts, etc. Really! Well that's interesting. OK so I found a nice reference sheet for 8620 steel which includes heat treatment information. According to this sheet, annealing requires "Heat to 820°C – 850°C Cool in furnace" and for normalizing, "Heat to 900°C – 925°C Cool in still air" So if Brekelefuw did the latter (and it sounds like it), he's now got a normalized piece of metal but not an annealed one. Fortunately, it's not air-hardening, so it's not any harder either. The sheet also says: quote:Forging: So, it's certainly forgable stuff, but you need a good heat and have to stop when it gets down to 850. That's assuming it's 8620 or similar, of course.
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Dec 23, 2012 20:40
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I know for sure they also make stainless keystock and they probably make low alloy as well. But good, factory hard keystock that you generally cut in a chop saw is probably a 4X40 or 86XX alloy IMHO. (I am only a senior in mech E, but an awesome one) EDIT: This question triggered my "I hate inaccurate answers" or "sperg" mechanism. McMaster Carr's options are 18-8 for stainless and "spring steel". Spring steel is usually A228. Amazon sells a "low carbon" and 1018 keystock. MSC offers it in Low, Medium and Tool Steel. The Low who cares you can't heat treat it, Id bet the medium is 1018/1020, and the Tool Steel is spec'd as W1 Lord Gaga fucked around with this message at 21:12 on Dec 23, 2012 |
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Dec 23, 2012 21:04
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You guys are probably aware this product exists, and cheap, but I'll share it with you anyways. You can get laser thermometers for like $20!! I'm going to snag one for when I start my quality control job in the new year. http://m.miniinthebox.com/digital-infrared-thermometer-with-laser-sight-50-c-550-c-58-f-1022-f-_desc_p200935.html It would likely be really useful for a smiths heat treatment needs.
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Dec 23, 2012 23:43
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It says it goes up to 550℃ which is fine for heat treating (and a good deal at $20), but a smith would probably want something that goes a bit higher for general purpose. I'd say at least the α-ferrite temperature (910℃ for pure iron) and ideally more like 1500℃. I don't know if that's even possible with a laser thermometer though. Probably not. There are relatively expensive IR thermometers that can do it, like this one. $240 is nothing to sneeze at though. e. This one goes to 1050℃ for $100 which I'd say would be pretty useful. Leperflesh fucked around with this message at 00:53 on Dec 24, 2012 |
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Dec 24, 2012 00:51
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More pictures! I went in to work today. I made 4 tapered tube closing dies (no pictures of those.) I also made a mouthpiece receiver for one of my trumpets (it's where you put the mouthpiece) First I measured the mouthpiece shank every 1/4 inch or so to select my drill bits and decide how deep each cut would be. After I step drilled, I got out my new MT#1 reamer!   Next I tested the mouthpiece in the hole to make sure the tapers matched. I used dry erase marker to make sure it was holding along the entire length of the taper.  Starting to decide on the design/profile of the receiver.   The final design of the piece. After the rounded end, there are 3 slight tapers. a 2 degree taper, a 5 degree taper, and then a 1 degree taper. I chose those angles because I am a music nerd and a 2-5-1 is one of the most common chord progressions in music. I left it a bit long so I had something to hold in the lathe while I worked on it. I used a parting bit and buffed and scratch brushed the piece.  And here we have it dry fit on to the trumpet.  I didn't have a chance to resolder the horn and play test it. ps. The bearing tool that I made in my last post works amazingly. If any of you use a lathe regularly, you should make one. It makes the most wobbily workpieces spin straight in seconds.
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Dec 24, 2012 01:36
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Rapulum_Dei posted:That gas forge looks very tidy, is it something you bought or made Slung Blade? gently caress, sorry, I forgot to answer your question! I bought that one, it's from Chile Forge. Specifically the Habañero one, middle sized. http://www.chileforge.com/ I regret not getting the bigger Cayenne model, the extra width would have come in handy many times. But this one has served me very well. The option to run single burner is great, saves me gas when I'm just doing short pieces, or want more localized heat. Fortunately, my old charcoal forge works just fine for bigger pieces, so I don't need the bigger one all that much.
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Dec 24, 2012 07:09
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I have a couple things to respond to from earlier in the thread. 1. Yumbo's log splitter is god drat awesome. 2. I agree with Ambrose Burnside, nothing wrong with beautiful elegant tools. 3. The really important thing to keep in mind when annealing and normalizing is to bring it up hot enough that it changes structure. The exact temperature is slightly different dependent upon how much carbon is in your steel. (I only know about carbon alloys.) When you bring the steel up around 1400 degrees it changes from one allotrope to another. (Diamonds and graphite are examples of allotropes of carbon.) A few things happen within the steel when this occurs. The crystalline structure changes, the metal becomes paramagnetic and the grain boundaries reset. The metal becoming paramagnetic is very useful. You can check if your metal is hot enough by using a magnet. If you don't bring it above this critical point you are not doing much to change the composition of your metal. Once this occurs you can cool it slowly by placing it on a hot brick or into vermiculite, or by whatever method you please. The trick is to remove the metal from the heat at about 50 degrees above the phase change. Once the metal has gone through a phase change the grain boundaries begin to grow. Small grain boundaries are ideal because deformations withing the metal occur within the boundaries of the grains. The bigger the grains the bigger your potential deformations. Normalizing is very much like annealing, except you are reseting the grain boundaries multiple times. I don't know the advantage of that over annealing. I've only normalized a couple of times with blades. Edit: The slower you cool the metal the more likely it is that your metal will form a very stable, even crystalline structure. ArtistCeleste fucked around with this message at 18:41 on Dec 24, 2012 |
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Dec 24, 2012 18:30
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Well, my holiday project plans have com to a halt. I can't seem to make a smooth cut on steel rod on the lathe we have at work. I sharpened my bits, tried a different bit, and no matter what, it cuts so uneven with tons of score marks. I don't know whether the lathe is not rigid enough or what. I am taking mayb 2-5 thou cuts and it still scores the steel. It cuts brass to a mirror finish though.
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Dec 26, 2012 23:15
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Brekelefuw posted:Well, my holiday project plans have com to a halt. I can't seem to make a smooth cut on steel rod on the lathe we have at work. I sharpened my bits, tried a different bit, and no matter what, it cuts so uneven with tons of score marks. I don't know whether the lathe is not rigid enough or what. I am taking mayb 2-5 thou cuts and it still scores the steel. It's the steel not the lathe. Try putting a larger radius on the cutting tool and moving faster with the feed.
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Dec 26, 2012 23:18
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What do you mean by a larger radius?
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Dec 26, 2012 23:47
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Brekelefuw posted:What do you mean by a larger radius? Cutting tools should have a radius at the contacting edge, a sharp one will just break, make that radius larger.
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Dec 27, 2012 02:24
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Yeah, U shaped, not V shaped. Heat build up, spalling off the tip, etc etc. Lots of poo poo happens when it's too pointy.
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Dec 27, 2012 04:15
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I was taught to grind my general cutting lathe bits with an 8-12 degree clearance on the cutting edge, 40 degree angle on the nose, and 8-12 degree rake angle on the top. Should I cut a new tool and roll the cutting edge so it is not a sharp angle?  This is the design that I have been using. Hopefully you can make it out. The cutting edge is straight and sharp. It is, as far as I know, the standard design for grinding your own stuff. OR do you mean I should grind something like letter C in this picture: 
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Dec 27, 2012 04:15
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The diagram from the book, with a radius somewhere between C and A and B, Notice it says finishing cuts, The radius makes the finish better on manual machines, On CNC you finish cut with a finer radius.
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Dec 27, 2012 05:56
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To perhaps clarify a bit, just under step 3 in bottom right of the picture of the book, it says 1/32 Rad. I suspect you might be grinding that corner sharp. If so, start at 1/32", and work your way up until you like the finish. Grinding HSS cutting bits is probably some of the cheapest education in machining.
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Dec 27, 2012 06:21
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Ill give that a shot tomorrow. My machining teacher told me to keep the cutting edge totally flat, and to grind up to it, but not actually touch it. The thing that is confusing me is that on the big lathes in the class workshop (Hardinge, South Bend, and modern standard) my tool bit cut really well, but on the Myford ML7-r we have at work it cuts like crap.
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Dec 27, 2012 06:46
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While I try to find a source for coal/charcoal I've been using my new hand crank forge blower (Thanks iForge!) to start the fireplace every morning. It's like cheating, it takes less than 3 minutes to get a good bed of coals going.
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Dec 27, 2012 17:51
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Brekelefuw posted:Ill give that a shot tomorrow. Is it a different kind of steel? Stainless 304 is sticky as gently caress and really hard to get a good finish on. also, Hardinge and South Bend are really really high quality machines, the Myford I've never even heard of.
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Dec 27, 2012 22:30
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Random Number posted:Is it a different kind of steel? Stainless 304 is sticky as gently caress and really hard to get a good finish on. also, Hardinge and South Bend are really really high quality machines, the Myford I've never even heard of. It's standard cold roll. Mild steel I guess. I tried a rounded bit today. Same result. I guess my plans for my holiday are shot. I don't have access to another lathe to use whenever I want, so I am not sure what to do. Maybe I will just have to hire someone to do my work for me.
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Dec 28, 2012 00:46
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Myford makes an excellent machine, they typically command a premium around here. So as long as it is in decent condition I wouldn't expect it to be giving you problems.
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Dec 28, 2012 02:28
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Colonel K posted:Myford makes an excellent machine, they typically command a premium around here. So as long as it is in decent condition I wouldn't expect it to be giving you problems. I think that brand is made in England which might be why it isn't something folks here are familiar with? https://www.youtube.com/watch?v=jnSlJeYgY2w
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Dec 28, 2012 03:28
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Yeah, it's the English equivalent of the South Bend here.
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Dec 28, 2012 15:22
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http://www.lathes.co.uk/page21.html is a good way to spend a coffee break if you're interested in lathes.
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Dec 29, 2012 00:50
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So does anyone remember when my old neighbour gave me this 220v hydraulic power pack? I sure do, because it's been taking up room in my garage for ages now and I felt bad about leaving it sit idle. Time to do something about that, starting with ordering parts. Huh, this is a nice little crate. Classy.       So, a 90 or 100 ton hydraulic cylinder depending if you go by the crate or the documentation. 2.5" travel on the stroke, single acting. Six centimeters and change doesn't really sound like a lot of travel, but it will be more than enough for forge press work, I can easily punch holes for hammer heads in that, and work bars bigger than what I can stick in my forge easily. I'm going to base the design of the frame on Kevin Potter's awesome single piece press:  No structural welds to fail under tension. Just *slightly* safer than those janky looking 50 ton presses you see at Harbor Freight or Princess Auto. Unfortunately, his only go up to 50 ton with 1" thick frames, which is still crazy powerful, but I'm going to get mine cut out of a piece of at least 1.5" plate, maybe thicker (thoughts?). The supplier I bought the cylinder from tells me these things work just fine mounted upside down, so I might do that and keep the scale away from the hydraulic hose (they will be shielded and wrapped up too, poo poo's dangerous, I know). Also it will have to be tall enough to hold the platens, the cylinder, the tooling, and filler plates so I can reduce the distance between the platens at will. The valve on the power pack was originally meant for double acting cylinders, so I think I will have to change that out. Gonna need all new hoses, a high pressure gauge probably, UHDP platen guides, a neat movable stand, enormously heavy platen bolsters and fillers, and some really hefty return springs. What do you guys think, what's the minimum distance I want between the platens? I'm thinking at least 30 cm / 6ish inches. It's fairly easy to reduce that distance, but impossible to make it bigger once the steel's cut, so I need to think about this and get it right. I've been using this thread like one of those psychotic unboxing threads over in TFR. I guess I'm the crazy one this time. If all else fails, at least I can use it to lift houses 
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Dec 29, 2012 01:04
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Goddamn that looks like it's gonna be a hell of a thing. Won't give advice on it 'cause I don't have any experience and any advice I give is liable to kill you. Will say that 6 inches is probably a reasonably safe bet for the platens, if not particularly generous- I have no idea what you wanna do with it, but that seems like plenty if you're not doing fancy super-deep die-forming operations or whatever. Bear in mind that for (comparatively) extremely light jewellery silhouette die-forming operations you're talkin' a urethane pad of about an inch but potentially much deeper if you're usin' soft urethane, plus however deep the die is. The odds of having to sink something 3 inches deep (which you'd need the die, plus at least as much urethane in thickness for) ain't huge unless you're making bowls or something. This is all probably moot for other methods, but I'd bet fixed traditional dies take up at least as much room. If it's just for forging with fullers you can swap out or whatever then consider the height of each fuller and then how much room that leaves you for swinging the metal stock into position. Is there any disadvantage to giving yourself more room to work with? If not, I'd shoot for most of the cylinder's fully-extended length, but again, maybe don't listen to me so much, preferably at all???
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Dec 29, 2012 03:57
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The UHDP is for the guides that slide up and down the body and keep the plate from touching the frame. It's kind of hard to see on that image from Potter, but there are little white plastic bits on each side: Wasn't looking to use any plastic in the tool area though, am I misunderstanding you? Only disadvantage to having more distance is that I need more blocks of iron to fill the gap when I work with smaller pieces. e: oh, also, the more blocks I need the higher the chance it'll go cockeyed and shoot out at me with an insanely high amount of force. Slung Blade fucked around with this message at 05:17 on Dec 29, 2012 |
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Dec 29, 2012 05:09
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I wasn't talking about those clippy thingies, the urethane thing was just a component of the only hydraulic die-forming operation I'm familiar with and can actually comment on, talking about how much room to leave between the platens. ahhhhhh I just saw it only has a 2.5" traverse. Dang. That -does- change things for you, I'm familiar with the much smaller presses with cylinders that have a much, much longer travel range, seeing as how they're born from bottle jacks. Okay, ~definitely~ don't listen to me.
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Dec 29, 2012 20:36
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 Cutting glasspacks out of some mufflers.
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Dec 30, 2012 02:42
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Made some more progress on my table today. Huh, this one stands up on its own, that's probably a good sign.  Fit up.   Tried it in the hallway to see how it looks. I mashed the legs out of any sort of alignment when I was hammering the tenons down, so that's going to need adjustment. You can see that front left arm came right out from under the tabletop. gently caress.  I'll finish leveling it out and paint it tomorrow when I can see. Sun vanished at 4:30 or so this afternoon. 
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Dec 31, 2012 02:24
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Slung Blade posted:So does anyone remember when my old neighbour gave me this 220v hydraulic power pack? Isn't that a ~3000 psi pump?
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Dec 31, 2012 15:15
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Chauncey posted:Isn't that a ~3000 psi pump? Ah, you're thinking the pump is 3000 psi and the cylinder is 10k? Good point. I'll go check next time I'm out in the garage. I can always replace the pump though if I have to (I think). I was going to get all new hoses and a different valve anyway.
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Dec 31, 2012 19:54
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Slung Blade posted:Ah, you're thinking the pump is 3000 psi and the cylinder is 10k? The cylinder is 100ton, which is 200,000lbs. Divided by the area of the piston (~44in if the internet is right) you'll need at least 4550psi (4100psi if it's 90ton) to use the cylinder to its maximum capacity. With your current pump at 3000psi you could only get a measly 66tons out of that cylinder. What a sissy little pump. Only 66tons. Hang your head in shame.
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Jan 1, 2013 00:15
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ductonius posted:The cylinder is 100ton, which is 200,000lbs. Divided by the area of the piston (~44in if the internet is right) you'll need at least 4550psi (4100psi if it's 90ton) to use the cylinder to its maximum capacity. 2'5" is nothing to write home about, either.
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Jan 1, 2013 00:57
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ductonius posted:The cylinder is 100ton, which is 200,000lbs. Divided by the area of the piston (~44in if the internet is right) you'll need at least 4550psi (4100psi if it's 90ton) to use the cylinder to its maximum capacity. Ehnn, where'd you get that number? Mine's the 1002: 
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Jan 1, 2013 01:50
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