Derek Melton Posted April 11, 2017 Share Posted April 11, 2017 I've been making some small hammers for jewelers and knife makers who need small, delicate hammers for detail work. I've been asked to make them even smaller, so I'm considering some from 3/8 inch round bar. Anyone have ideas for tooling, techniques for punching eyes in small round bar? It's kinda tricky. =) Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted April 11, 2017 Share Posted April 11, 2017 I'd go with slitting and drifting rather than punching. Quote Link to comment Share on other sites More sharing options...
Will W. Posted April 11, 2017 Share Posted April 11, 2017 What Thomas said. If you insist on a round hole, you could always drill a small hole and drift from there. Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 11, 2017 Share Posted April 11, 2017 Slit and drift larger stock and forge it down to the desired dimensions. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Alan Evans Posted April 11, 2017 Share Posted April 11, 2017 I use a combination slot punch and drift. The long axis length of the slot punch is the same as the final diameter (or long axis if left oval for a handle) of the hole. The width of the punch is a narrow as you can get away with. With Ø3/8" parent bar you really need to to be less than 1/8". I profile the punch end with a tight radius so that it acts as a fuller and spreads the metal to either side without elongating the bar. Thus keeping as much metal either side of the hole as possible and obviating the need to upset. If you wish to pass a larger diameter bar than the parent through the hole you must use a longer punch and allow for the bar to reduce in length. You would make life a lot easier for yourself if you used 3/8" square and then octaganise or round the head and pein after punching the hole. With round bar you need to start off with the bar in a swage, and I quite often create a flat spot with a full faced hammer or punch in order to create a facet for locating/starting the punch. This was a Ø21mm clearance hole through Ø20mm (Ø3/4") 316 SS made with the same proportion of slot punch. Any larger diameter hole and there would be a noticeable wasting of the metal where the hole meets the parent bar. Alan Quote Link to comment Share on other sites More sharing options...
Derek Melton Posted April 11, 2017 Author Share Posted April 11, 2017 Wow, thank you! I made a new slitter/punch last night that was the same 3/8 diameter. I forged the end down to a typical slot punch shape and then I cut it about 3 inches short and welded it to a 14 inch section of 1/4x3/4 for a handle. I plan on trying it tonight. I'll post here with results. Quote Link to comment Share on other sites More sharing options...
beammeupscotty Posted April 12, 2017 Share Posted April 12, 2017 If I were going to make such an item, I would make it from something like 3/4" material so I could get something like a legitimate eye, then forge down the ends to the requisite 3/8" section. Quote Link to comment Share on other sites More sharing options...
Derek Melton Posted April 12, 2017 Author Share Posted April 12, 2017 I agree, larger stock forged down on the ends would work better, I was just curious as to how one would turn out, somewhat as a novelty, from such small round bar. I was really pleased with it. Until it broke. This was my first attempt at the tiny hammer. Being 5160, I just heat treated it as I always had, heated to critical, quenched in oil, tempered at 400. The grain structure of the steel where It broke looked just like a file, kinda creamy and fine. I think it was just too brittle and my temper didn't work out. I worked on a new slit/drift combo for the 3/8 round bar last night. It worked well, I really appreciate the suggestions from Alan Evans regarding the proper diameter of the drift in relation to the stock. I'm going to make the same kind of tiny hammer, this time I'll keep the eye a little smaller and I'll only heat treat the working faces, not the eye material. Quote Link to comment Share on other sites More sharing options...
Farmweld Posted April 12, 2017 Share Posted April 12, 2017 Alan, would you please post some pictures of your slit/drift tools. I ask because I did some volunteer work in a musuem at Riverton in South Australia which was the original town smithy and wheelwrights shop. There were some slit/drift tools on one of the benches which had been made from various different bits of tool steel, including old files and rasps, which it took me a while to work out were exactly what you are describing. Most of these were probably used on wrought iron from the age of the smithy, and they were definitely one way tools which you would have to put all the way through in one heat as a big one went from a slot about 35mm long and 4-5mm wide to a 25mm dia hole in one continuous punch about 250 - 300mm long. There was a distinct neck behind the slot where it transitioned from rectangular to oval to round. I've been trying to work out a way of making smaller ones for the smaller sizes of steel I use and it looks like you are achieving the sort of result I am after. Regards Andrew Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted April 12, 2017 Share Posted April 12, 2017 400 degF? That's more a knifeblade temper range and not an impact tool temper range! 400 degC? (752 degF) would be kinda hot for an impact tool of that alloy... Quote Link to comment Share on other sites More sharing options...
Derek Melton Posted April 12, 2017 Author Share Posted April 12, 2017 6 minutes ago, ThomasPowers said: 400 degF? That's more a knifeblade temper range and not an impact tool temper range! 400 degC? (752 degF) would be kinda hot for an impact tool of that alloy... Yeah, 99% of my experience with 5160 has been with knives. I've made some punches and hand held drifts/fullers with it but I usually temper those by color. What would you suggest for a temper? Just bring it to a straw and quench or pop in an oven for a particular time/temp? Quote Link to comment Share on other sites More sharing options...
stockmaker Posted April 12, 2017 Share Posted April 12, 2017 Nice little hammer Derek. Having the right hammer for the job is not only important in blacksmithing, but in other endeavors as well. The right little hammer is as important to me as the right chisel or file. I have wondered lately if there is a market them at craft shows? A picture of my workbench this morning. Quote Link to comment Share on other sites More sharing options...
Derek Melton Posted April 12, 2017 Author Share Posted April 12, 2017 17 minutes ago, Derek Melton said: Yeah, 99% of my experience with 5160 has been with knives. I've made some punches and hand held drifts/fullers with it but I usually temper those by color. What would you suggest for a temper? Just bring it to a straw and quench or pop in an oven for a particular time/temp? I probably answered my own question there, I probably should just heat treat the working faces, temper by color as I do with other 5160 hand tools. Once I get the next hammer finished, I'll test it on the anvil too and I'll know if my process is working or not. =) Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted April 12, 2017 Share Posted April 12, 2017 If you need an extremely hard face then straw would work; but you should be drawing the body back to say a blue; Otherwise I would draw to peacock or even blue depending on requirements Quote Link to comment Share on other sites More sharing options...
Derek Melton Posted April 12, 2017 Author Share Posted April 12, 2017 3 minutes ago, stockmaker said: Nice little hammer Derek. Having the right hammer for the job is not only important in blacksmithing, but in other endeavors as well. The right little hammer is as important to me as the right chisel or file. I have wondered lately if there is a market them at craft shows? A picture of my workbench this morning. Thanks! I love doing it and while I'm still a rank amateur, I want to learn and make each one better than the last. I think this is hammer #11 so I've got a long way to go. =) Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted April 12, 2017 Share Posted April 12, 2017 If you find that you are selling most of your stuff during setup or teardown days then you know that you are generally selling to other crafters and *they* think your stuff is well made at a good price. Quote Link to comment Share on other sites More sharing options...
Derek Melton Posted April 12, 2017 Author Share Posted April 12, 2017 4 minutes ago, ThomasPowers said: If you find that you are selling most of your stuff during setup or teardown days then you know that you are generally selling to other crafters and *they* think your stuff is well made at a good price. I've sold only one so far but I've given several away to close friends and asked them to use them and report back any shortcomings, etc. so far, this is the only one that has failed and it failed before it left the shop so, it's served a pretty valuable purpose already. Quote Link to comment Share on other sites More sharing options...
beammeupscotty Posted April 13, 2017 Share Posted April 13, 2017 It that a Canarywood handle? Quote Link to comment Share on other sites More sharing options...
Derek Melton Posted April 13, 2017 Author Share Posted April 13, 2017 17 minutes ago, beammeupscotty said: It that a Canarywood handle? Good eye! Quote Link to comment Share on other sites More sharing options...
Jasent Posted April 13, 2017 Share Posted April 13, 2017 Tagging along. I've made one small hammer sofar. Used it to pound out this SS shop ladle. Plans for many more. Ps grain does not go side to side this are saw tracks Quote Link to comment Share on other sites More sharing options...
Alan Evans Posted April 22, 2017 Share Posted April 22, 2017 On 12/04/2017 at 0:52 PM, Farmweld said: Alan, would you please post some pictures of your slit/drift tools. I ask because I did some volunteer work in a musuem at Riverton in South Australia which was the original town smithy and wheelwrights shop. There were some slit/drift tools on one of the benches which had been made from various different bits of tool steel, including old files and rasps, which it took me a while to work out were exactly what you are describing. Most of these were probably used on wrought iron from the age of the smithy, and they were definitely one way tools which you would have to put all the way through in one heat as a big one went from a slot about 35mm long and 4-5mm wide to a 25mm dia hole in one continuous punch about 250 - 300mm long. There was a distinct neck behind the slot where it transitioned from rectangular to oval to round. I've been trying to work out a way of making smaller ones for the smaller sizes of steel I use and it looks like you are achieving the sort of result I am after. Regards Andrew Hi Andrew sorry it took so long, went away for a few days over Easter. Herewith the punch profile I use. The important thing about the punch and drift combination is that the tip width/slot length is the same as the final diameter...you can see the sides of the the punch are parallel top to bottom. Otherwise you cannot get it out! The form of the punch is fairly simple you could make it just by stock removal...I always forge them because it quicker, and then I have the heat for an oil hardening. The tip is radiused in both directions. I normally just make them flat and relieve the corners. The heat/wear of use takes the corners off and radiuses the punch and they become more and more efficient. Having reached the optimum heat conducting profile they do not deform any further. I have explored a number of different transition profiles over the years. Rectangles with rounded ends through ovals and ellipses but the common rule for all of them has been to ensure there are no sharp edges or corners, everything is radiused. In the photo below you can see some of the variations. There are a couple of facetted ones that drifted out to an octagonal hole. The wedge facets have been both flat, convex and concave and soft facetted but makes little difference. So the more recent ones are simple flats. The concave surface does help release the punch on the big punches going through 60mm (2.5") square and up. Alan Quote Link to comment Share on other sites More sharing options...
Alan Evans Posted April 22, 2017 Share Posted April 22, 2017 Forgot to say that of course the above punches are for the hydraulic press which has a Ø1.5" chuck. So they do not go straight through like the ones you used. I have made some like that, but if I need a longer slot I tend to do it with two tools, a dedicated slot punch and separate drift. I also refer to these as slot punches as opposed to slit, these punch out a slug whereas my slitting chisels are sharp edged and do not remove any metal, just cut through it. Alan Quote Link to comment Share on other sites More sharing options...
jlpservicesinc Posted April 22, 2017 Share Posted April 22, 2017 21 hours ago, Alan Evans said: Hi Andrew sorry it took so long, went away for a few days over Easter. Herewith the punch profile I use. The important thing about the punch and drift combination is that the tip width/slot length is the same as the final diameter...you can see the sides of the the punch are parallel top to bottom. Otherwise you cannot get it out! The form of the punch is fairly simple you could make it just by stock removal...I always forge them because it quicker, and then I have the heat for an oil hardening. The tip is radiused in both directions. I normally just make them flat and relieve the corners. The heat/wear of use takes the corners off and radiuses the punch and they become more and more efficient. Having reached the optimum heat conducting profile they do not deform any further. I have explored a number of different transition profiles over the years. Rectangles with rounded ends through ovals and ellipses but the common rule for all of them has been to ensure there are no sharp edges or corners, everything is radiused. In the photo below you can see some of the variations. There are a couple of facetted ones that drifted out to an octagonal hole. The wedge facets have been both flat, convex and concave and soft facetted but makes little difference. So the more recent ones are simple flats. The concave surface does help release the punch on the big punches going through 60mm (2.5") square and up. Alan Nice work Alan, What steel are the punches made out of? Hydraulics offer so many advantages if used appropriately.. Quote Link to comment Share on other sites More sharing options...
Alan Evans Posted April 22, 2017 Share Posted April 22, 2017 2 hours ago, jlpservicesinc said: Nice work Alan, What steel are the punches made out of? Hydraulics offer so many advantages if used appropriately.. Progen, oil quenched, no temper. It is no longer made I understand. I happen to have a tonne of it bought just before the end of a good financial year...still got most of it! I think you have a near equivalent in the Flutagon military field tool steel. There was a thread some time ago which had some info about it https://www.iforgeiron.com/topic/44724-hot-forging-punches-material-treatment/#comment-463081 Progen is very forgiving and tough. Hard and fine grain enough to make razor blades! I sent Hofi the punch design and he had some made out of solid carbide which must have been great. Lower friction and no deformation. With my Progen ones I started off making them with a flat bottom and was paranoid about keeping it that way, sanding them back to profile after every two or three holes. After a few holes they round out and build up a mushroom end. After a few years I learned to relax about it, and do not bother to ever dress them now. The funny thing was that I noticed with a mushroomed end they released a lot easier on the upstroke...there was only contact on the sides of the mushroom, and not the friction of the wedge engaging with the entire thickness. I also realised that the mushroom was not the punch deforming but layers of mild steel from the workpiece welding themselves to the punch...they would build up and then come off and the punches never got shorter! Hofi's carbide ones would probably just stay the same but the softer Progen turned out to be fine. I developed the punch, the hydraulic system and the furnace for the Public Record Office commission. 12metres wide plus side panels...A lot of holes which had to line up! It made a huge difference for production.From two men getting 16 holes done a day with a coke fire and power hammer, with some of them going awry...to one man doing 42 holes in one day with every one accurate length and centred. The punch system was also used on the Big Market gates and that was all quite heavy stock. As the movies say, no punches were harmed in the making of these projects. Slightly over the top given the thread title, but you asked! Alan Quote Link to comment Share on other sites More sharing options...
Dogsoldat Posted April 23, 2017 Share Posted April 23, 2017 Wow!!! That is some impressive work in those gates Quote Link to comment Share on other sites More sharing options...
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