patrick

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About patrick

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  • Gender
    Male
  • Location
    Janesville, WI
  • Interests
    Mokume, Tool Making, Industrial Forging

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  • Location
    Beloit, WI
  • Interests
    Forging of all types
  • Occupation
    Metallurgist

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  1. patrick

    coupla chunks

    I wonder who that was. I had a professor and lad assistant who were both former Battle guys.
  2. Yeah carbon content s that high usually are not carburized. Those grade usually are limited to 0.3 carbon. Higher carbon in the base material has less driving forced to absorb more carbon. Also by keeping carbon low in the base material you get better core toughness.
  3. Given the alloy it is most likely induction hardened. It can be annealed as Thomas noted but you don' have to worry about scaling away the high carbon layer because the carbon content will be fairly uniform throughout the pieces.
  4. The double key system is the simplest to set up and cut on either a shaper or a mill. If you can cut a straight line on you mill all you need is a custom made dove tail cutter and and end mill. Rough out with the end mill and finish with the dovetail. If your dies are not long you can get a long bar and in a single set up mill the dove tail down the whole length of the bar. Cut the dies to length after milling. Bradley used a 5 degree dovetail angle with about an 1/8 radius in the corner. Keys were tapered 1//8 inch per foot. I had a customer cutter made by a local tool cutting shop. I think it was around $100 but it was made from a 2 inch diameter end mill I supplied. If you're using a a brigldgeport type mill you probably won' go over one inch diameter. You might consider having it made from carbide if you mill has the speed to take advantage of that.
  5. I suggest you use a double key system. In that method the dovetail in both the die and sow block is straight and centered. One wedge goes on each side of the die but in opposing directions. This system was used on Bradley' and works great.
  6. For a press that big I suggest you make dedicated tooling separate from the power hammer.
  7. patrick

    Navy Hammer sell off

    I forgot to mention that when our hammers were converted to air they redid the seals. The seals for air hammers have a closer fit than those for steam hammers. I' sure you can run them on air without this alteration but they won' be as efficient.
  8. patrick

    Navy Hammer sell off

    A couple of things: 1. Steam hammers can be converted to air and run just fine that way. Scot Forge made that conversion to their hammers probably 8-10 years ago and they work great. No lose of power and the operators actually like it better because then don't have hot water dripping on them while they are working. 2. Large forgings are still produced for the navy. Scot Forge makes many of them now as do some of our competitors. 3. Material handling in a modern forge shop is nothing like what you see in the old black and white videos. Tongs are still used but only for very small parts or for small tools. Otherwise various specialized machines are used. This is both for improved safety and efficiency. 4. Forging and anvil is a wonderfully romantic idea and I've thought about it myself many times. To get to a traditional anvil form you need a two piece construction that is either arc or forge welded at the waist. Casting an anvil is a much more efficient want to make one and, provided the heat treatment is done correctly, will give equally good performance to a forged anvil. 5. I'm pretty sure the Navy shop pictured earlier in this thread didn't have that many smallish hammers in it. It has been known for a number of years that this shop was going to be sold. I believe one of my collegues was able to arrange for a 300lb hammer to be donated to the university of Missouri-Rolla, to promote their metallurgy/materials courses. In general, shops like this did large scale work and the small hammers that were in the shop were there to make tongs and test bars. There are still a few shops around with this type of arrangement. Clifford Jacobs and Ladish are a couple of examples. For those interested in seeing really excellent videos of modern forge work, both on presses and hammers, visit the Scot Forge website
  9. What a cool hammer! Thomas did contact me about this since I am running Bradleys which use a similar rubber cushion system. I did not have to replace my cushions but when I was looking into options for that (just in case I would need to) I found most sources to be quite expensive. I believe Bob Bergman can get them, I'm sure that the folks at Cortland Machine in New York could also do it since they supply parts, including cushions, for Bradleys. I know that Stuart Giesler had some new old stock cushions for Bradleys available at one time. I would measure the ones you have and compare with what he has. You might be able to modify the Bradley cushions to fit your machine. Another method is to make your own. I have heard that RTV pourable resin works very well in this application. I would contact Ray Rybar, a very talented knife maker, for info on this product and the process he has used. I'm told he's made new cushions for quite a few Bradleys with this product and has had very good success at very reasonable prices. Good luck.
  10. The hammer makers I know buy round bar and convert it to the sizes they need. Nathan Robertson has made something like 5500 hammers this way.
  11. For M2 you really do have to get it extra hot to heat treat it becuase you have to dissovle the complex alloy carbides prior to quenching. With simple steels those are just iron carbide and will dissolve around 1450 F but once you start putting in vanadium, molydinum etc you really have to raise the temperaure.
  12. It's been a while since I've posted here so I'll briefly provide my background before answering the original question. I am a professanal metallurgical engineer and have been working as the plant metallurgist for one of the Scot Forge facilites for the past 14 years. We make forgings up to about 150 tons these days. Prior to that I worked for Timken for 2 years. I've been forging by hand and with power hammers for the last 20 years. Hat tip to Thomas Powers who got me started... The orginal question had to do with a precieved difference in strength between forged blades and those ground directly from bar which lead to a more general discussion of the various merrits of forged products vs. those produced by other methods. To properly answer this question we first have to define "strength". There are multiple types of strength and ways of measuring it. Tensile properties are determiend by stretching. There are 4 properties tyically obtained from a tensile test: Ultamate tensile strength, yield strength, elongation and reduction of area. Utimate tensile strength: The maximum load applied before the specimen breaks Yield strength: The load necessary to cause permanent deformation of the specimen Elongation: The % change in length from the starting length to the final length after the specimen breaks Reduction of area: The % change in cross sectional area from the starting area to that after the specimen breaks. Additoinal Types of Strength: Fatigue Strength: The ability to withstand repeated bending when the amound of bend does NOT result in any plastic deformation Imapct strength: A measure of the amount of energy needed to break a notch bar specimen of standard dimension. This property is temperature dependant for the carbon and alloy steels under discussion here. When comparing forgings to products made from machined bars, assuming that is the only difference is in how the shape was achieved, the differences in "strength" will not be differences in utimate tensile or yield strength. Nor will there be differences in the elongation, reduction of area or impact strength. The difference will be in the fatigue properties. The reason for this is becuase in a forged product, the metal is forced to flow around corners. This flow around the corners does align the non-metallic inclusions in the streel in a preferential way which results in resistance to fatigue failures. It is true that steel today is not like steel from years ago and is particularly different from wrought iron. It is much cleaner so the behaviours we see in wrought iron are not encountered when hand forging steel. However, inspite of the much cleaner materials we have today most steel still has some amount of non-metallic inclusions. These are microscopic, but they still do affect properties. In particular they affect the elongation, reduction of area and impact properties. If you are dealing with a forged or rolled bar these micro inclusions are oriented in line with the long axis of the bar. If you cut a specimen parrellel to this axis you will get one set of properteis. If you cut your specimen at 90 degrees to this axis you will find that ultamite tensile and yield are about the same but the elongation, reduction of area and impact properties are reduced. Today it is possible to produce steel that is so clean you have very little difference in properties regardless of test orientation, but those materials are more costly to produce and are not as widely used. With respect to the original question where the starting stock is a rolled bar which is then either forged into a blade or ground into a blade there will be almost no measureable difference in properties assuming that is the only differnece in manufacturing. IF there are difference in heat treat then yes you can get major differeces in performance. Additional questions were raised about grain size and grain flow and there seems to be some confusion on these subjects: Grain size is the actual size of an individual crystal of iron. This is measured via standard methods and is given an ASTM size rating. The larger the number the smaller the actual crystal. In general smaller grains are prefered for most applications because smaller grained materials will have better elongation, reduction of area and impact properties. Industrially grain size is controlled through a combination of heat treatment and chemistry. Provided you have elements in the steel that limit grain growth during heat treatment (aluminum, vanadium, niobium) you can refine the grains by normalizing prior to austentizing for the quench. In industry there are times when multiple normalizing cycles are used for the purpose of refining the grains. Generaly we don't see a benefit to doing more than two cycles, and even that is a special case. Most of the time a single normalize cyle is sufficient. Grain flow is what I noted about about forcing the metal to go around corners. Edge "packing"-This is really a confusing term because you are not making the steel more dense. What you are doing is locally deforming and breaking the grains into smaller sizes. It is a technique that is not necessary with modern steels since grain refinement can be achieved through heat treatment.
  13. the primary reason to add nickel to the non-stainless steels is to increase their hardenability. Two bars of the same size but different compositon will have different hardenability. If the bars are large, say 10 inch diameter and one is 1045 and the other is a nickel bearing grade like 4340 you'll be able to make the 4340 much harder at the center than the 1045. This is important for industrial applications. 1045 has almost no nickel while 4340 has about 1.75%. Look up jominy testing and results for these two grades. That will help you understand what nickel does.
  14. Another good choice is Hobart hard alloy 58. This is the rod Hobart recommends for anvil repair. The southern ohio forge and anvil group has been using it for a couple decades at least for anvil repairs. It goes down hard and grinds easy. It is not work hardening. One thing you have to watch with work hardening rods is the fact that they go down soft and require deformation to get hard. The very abrasion resistant rods tend to be too brittle for anvils.
  15. patrick

    E52100 alloy steel ?

    The letter "E" prefix means the material is made by Electric Arc furnace steelmaking processes. There are other steel making processes such as those which make steel directly from Iron Ore. That would be what's done at the integrated steel mill using a blast furnace. Most steel today is produced by taking scrap and re melting it using an electric Arc furnace and so that "E" designates that the Steel has been made by that process. Patrick