will52100 Posted July 21, 2016 Share Posted July 21, 2016 I've forged several, but keep having issues. The first one I did from L6 and it worked great, except the eye folded over and collapsed when using the 5 pound hammer. I had heat treated this in the oven as it's got enough chromium in it to air harden. Also my stock was a little on the small side so I think I'd have been fine if I'd had thicker eye sides. I did cut the punch part off and weld it too a handle and turned it into a power hammer punch and it seems to be holding up well. The next one was from 4140 and it's got a nice crack right through the middle. It didn't show up until I was normalizing it in the forge. I forged two, and one survived, so we'll see how it works. All I had was 2"x1/2" stock, so I upset and flattened it into a 1" square, then punched and drifted the handle hole. I have forged 4140 before and it's the only steel I've worked that cracked on me. This time I made sure I was hot and didn't forge it at lower temps. What alloys would you suggest for a top tool like this? I've got 1045, 52100, and 4140. I may have some 5160 John Deere load shaft left, not sure. I've got a couple of punches I made that work well, but I'd like to have one with a handle for better control and to keep my hand away from the heat. Quote Link to comment Share on other sites More sharing options...
Gergely Posted July 21, 2016 Share Posted July 21, 2016 My vote goes for 4140. Happy hammering Gergely Quote Link to comment Share on other sites More sharing options...
Crazy Ivan Posted July 21, 2016 Share Posted July 21, 2016 I use 4140 for most of my top tools, eye punch included. I also use H13 for eye punches. When your punch cracked on you, I'm betting it split at the eye and down the length of the tool? I've had this happen to me once before on a 2"x2" piece. My guess is that I had too many heats into the piece which caused excessive grain growth, causing the crack while forging. I normalize between each step now and haven't had it happen again. Maybe it was just a fluke since it only happened once out of hundreds of tools and hammers from the same heat# but it still made me change my process, just in case. As to heat treating eye punches, I use them as normalized 5x. that's all. Quote Link to comment Share on other sites More sharing options...
will52100 Posted July 21, 2016 Author Share Posted July 21, 2016 Thanks, I figure your right about grain growth. I haven't forged much 4140 and I did not normalize until after forging to shape, and that's when the crack appeared. I'd already cleaned up the punch end on the grinder and there was no crack. I'll try again with multiple normalizing steps in between forming. I didn't intend to heat treat the 4140, the reason I did the first was it was L6 and if allowed to air cool from critical it gets in the high 50's rockwell. When heat treated right it's a super tough steel, but it's a pain to do since it really does need an oven for the best results. Quote Link to comment Share on other sites More sharing options...
Mark Ling Posted July 21, 2016 Share Posted July 21, 2016 I don't heat treat my hammeer eye punches, and neither does Brian or Alec, mainly because their is no reason to, because your going to lose the temper the first time you use the tool. were you using reclaimed 4140? If so the crack could have been pre-existing and you just didn't notice it until later. Littleblacksmith Quote Link to comment Share on other sites More sharing options...
will52100 Posted July 21, 2016 Author Share Posted July 21, 2016 It was virgin bar stock, the other I forged from it did not crack. The reason I heat treated the L6 is that it's hard as glass when air cooled after heating to critical. It is an air harding steel. I did not do a full heat treat, just annealed it. That in turn made the eye walls too soft for there thickness. It probably would have worked OK if I'd used a spring heat treat on the whole thing. Or had thicker stock to work with. The tip has handled heat very well. Quote Link to comment Share on other sites More sharing options...
Dave Budd Posted July 21, 2016 Share Posted July 21, 2016 the 4140 sounds the best bet with what you have. Rather than trying to get enough mass around the eye area, why not just wrap a wire handle (or weld it on if you must). That way you can get a 1" thick punch with no weak spot to break Quote Link to comment Share on other sites More sharing options...
will52100 Posted July 21, 2016 Author Share Posted July 21, 2016 I had thought of that, and have a few I've done, but part of it is I'm bound and determined to get the thing done and working. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 22, 2016 Share Posted July 22, 2016 5 hours ago, will52100 said: It was virgin bar stock, the other I forged from it did not crack. The reason I heat treated the L6 is that it's hard as glass when air cooled after heating to critical. It is an air harding steel. I did not do a full heat treat, just annealed it. That in turn made the eye walls too soft for there thickness. It probably would have worked OK if I'd used a spring heat treat on the whole thing. Or had thicker stock to work with. The tip has handled heat very well. Then that's a BAD choice isn't it? It's going to hit a nice red heat punching an eye even if you use the 3 blow and cool it rule. 5160 is pretty forgiving of heat mistreatment. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
will52100 Posted July 22, 2016 Author Share Posted July 22, 2016 No, because a red heat is below the critical temp. And even if you get the very tip to critical, your main body behind the tip is well below and will act to slow cool the tip enough to get it below the nose. Mainly though, a red heat is sufficiently below the critical temp to prevent hardening. Also, it's what I had available at the time. L6 is not designated as an air harding steel, but it sure does a good impression. I've left forgings sit and air cool after normalizing and it read 61 rockwell. S7, for example, is also air harding, as is H13, both steels used in hot forming. 5160 will also air harden to a certain point, nowhere near as completely as higher chrome steels like L6 or D2 though. When you forge something, you heat treat it, whether you are just thermally cycling as you heat it up to beat on it, or if you full quench and temper it. Seems I need to do a few more normalizing cycles on 4140 during forming. Quote Link to comment Share on other sites More sharing options...
will52100 Posted July 25, 2016 Author Share Posted July 25, 2016 Well, seems multiple thermal cycles while forging did the trick. I did a couple normalizations after forging the flat bar into square stock, then after initially punching the eye, and then after drifting, and again after forming the point. Every thing worked well, no cracks. I did quench it then bring it back to a sub critical heat and slow cooled. Made for a very durable punch and drift and works well so far. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 25, 2016 Share Posted July 25, 2016 I'm familiar with how steels react to heat and physical deformation. My comment was strictly about results not reading material properties articles. Your results don't speak to the materials properties but your techniques. An adjustment you've apparently made. No biggy we all get to play on the learning curve and it can be both steep and slippery. I have a number of punches, slitters and drifts made of 4140 and as long as I don't cool them in water after they reach a red heat they don't suffer embrittlement, nor do the hot tools made from old spring both coil and leaf. Both those alloys are pretty forgiving of eyeball shop heat treatment and work well with only a LITTLE care. Unless I'm mistaken both S and H series steels have MUCH higher critical temperatures that involves time. Annealing even normalizing is a process better suited for a precisely controlled ramping kiln. No? I don't know of folk making hot tooling with D or L series steels so I have no opinion not generated by your posts nor have I tried forging either outside incorporating some band saw blade (mystery alloy with Ni) in a pattern welded billet. I'm trying not to be adversarial I just want to fill gaps in my knowledge. It's mostly a yawning chasm of gap. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
will52100 Posted July 29, 2016 Author Share Posted July 29, 2016 No problem, and I think were on the same page there abouts. The reason I used L6 at the time was it was what I had on hand. I did anneal it in the oven to eliminate the air harding tendency after normalizing. In effect that made it too soft, and if I was to do it again I'd do a quench from critical then a high temper to give it just a little hardness instead of being dead soft. Likely somewhere around 800-1000 deg. to get a rockwell of about 45 or so. Still not the ideal material for the application, but it would likely work with better heat treating. The main issue is the two types of L6, one likes to air harden more so than the other, and that's what I had. I don't have a lot of hands on experience with the H or S steels, but the recipe for H13 calls for bringing up to 1600, equalizing, I assume the bigger the piece the longer soak, then quench. No real info on soak times like I run into with stainless. S7 on the other hand calls for a higher heat, 1700-1750 deg. F. and a 20 minute soak. The proper annealing cycles for H13 and S7 are a nightmare, 20-50 deg an hour cooling from critical, not something I want to screw with even with an oven. I've done air harding steels by hand and eye, but it's a lot of trouble and experimentation to figure out what works to get close enough. I really wouldn't want to be with out my oven for any of the L, H, or S steels now. The biggest issue is grain size, smaller grain generally means stronger, but it's tough to get small grain outside an oven with these steels. You can get them "good enough" though. I'm starting to really like the 4140, just took a bit of playing with it to understand how to work it. I've been making my hammers and top tools from 1045, now I'm thinking I will be making them from 4140. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 30, 2016 Share Posted July 30, 2016 I have a friend who picked up a pottery kiln he's modified to precision control for his mokume and heat treating blades. Even then we don't mess with the more exotic heat treat alloys. I'm a simple guy so about as exotic as I get is 4140 and the shop toaster oven is lab grade enough. I'm just glad I didn't come off pretentious enough to make a non-friend of you. I'm not as articulate as I was before the accident so I can get pretty heavy handed trying to express myself. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
will52100 Posted July 30, 2016 Author Share Posted July 30, 2016 No worries, it's hard to tell tone and pitch when reading typed responses, and I've been guilty of coming off as sharp when that's not my intention. I've got a Paragon oven and love it, but I primarily got it to do stainless. But I've found a lot of uses for it when heat treating carbon steels as well, even 1084 gets a set of reducing normalizing heats for grain refinement. I do normally use a slightly modified toaster oven for tempering, it's easier and cheaper to run than my oven. I'm coming at it from the opposite end, took a little getting used to mild steel and wrought iron after forging 52100, that stuff moves about as well as cold mild steel. Luckily I had a little 4140 to play with, used it for some hammer dies I made, other wise I might not have tried it. I'm slowly advancing, but I have to rethink a lot of ways of doing things after forging some of knife steels out there. Took a while to understand I didn't need 3, two hour tempers on a 1045 hammer head. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 30, 2016 Share Posted July 30, 2016 Oh man, all that's WAY more sophisticated heat treatment than I do, I'm about tapped at the toaster oven. I don't recall the temperature but I left my 4140 Little Giant dies in the toaster oven over night for a nice dark straw. So far in spite of some of the guys trying to tempt me I don't make blades unless I really REALLY need one. Most of my heat treatment is for shop tools, punches, chisels, etc. usually well within mark 1 eyeball range. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
will52100 Posted July 30, 2016 Author Share Posted July 30, 2016 I'm starting to learn you don't need that sophisticated a heat treat on punches and chisels and such. I'm coming at it from from the cutlery side of things where I am chasing high performance and have to stop myself from getting overly complicated when doing a drift or such. 52100, 5160, CPM steels, multiple quenches and thermal cycles, multiple 90 deg. bend test, rope cutting and such don't really apply that much to 1045 and 4140 and making a top tool or center punch and I'm starting to get that through my head. First hammer I made I was looking for a time/temperature chart to figure the expected rockwell at different tempering temps and couldn't find one, was having trouble wrapping my head around "just make it straw colored", but am getting there. Quote Link to comment Share on other sites More sharing options...
Frosty Posted August 2, 2016 Share Posted August 2, 2016 I know what you mean, I grew up in Dad's metal spinning shop where he did a lot of aerospace work and it took me years to stop thinking in 0.0001" increments. Heck I got interested in blacksmithing in part as relief from the insane tolerances we worked with all the time. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
will52100 Posted August 2, 2016 Author Share Posted August 2, 2016 That right there is one of the reasons I just about refuse to do folders anymore. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted August 2, 2016 Share Posted August 2, 2016 I'm a traditional smith and so work to a tolerance of the thickness of a worn shilling---now just to find one from the 1800's as a try gauge... Quote Link to comment Share on other sites More sharing options...
will52100 Posted August 2, 2016 Author Share Posted August 2, 2016 Now that's funny, but one of the reasons I'm liking just wire brushing the scale off. Quote Link to comment Share on other sites More sharing options...
JHCC Posted August 2, 2016 Share Posted August 2, 2016 11 hours ago, Frosty said: I know what you mean, I grew up in Dad's metal spinning shop where he did a lot of aerospace work and it took me years to stop thinking in 0.0001" increments. Heck I got interested in blacksmithing in part as relief from the insane tolerances we worked with all the time. Frosty The Lucky. Insane tolerances are why I stopped working in the violin repair shop. Totally driving me bonkers. Explains a lot, doesn't it? Quote Link to comment Share on other sites More sharing options...
Francis Trez Cole Posted August 19, 2016 Share Posted August 19, 2016 the best one I ever made was from a torsion bar. The hammer eye drift Brian makes is for a handle with flat sides. Quote Link to comment Share on other sites More sharing options...
Frosty Posted August 19, 2016 Share Posted August 19, 2016 On 8/2/2016 at 5:06 AM, JHCC said: Insane tolerances are why I stopped working in the violin repair shop. Totally driving me bonkers. Explains a lot, doesn't it? The bonkers part anyway. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Gorō Posted October 7, 2016 Share Posted October 7, 2016 For top tools; 4140 or h13 Quote Link to comment Share on other sites More sharing options...
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