meco3hp Posted July 23, 2005 Share Posted July 23, 2005 Hello, Been working in my buddies shop all day using his mill, welder, and lathe to turn out some tooling. I'm going back in the morning to make some spring dies, fullers and swages. I'll post some pictures Sunday. My first question is, on spring swages for round stock, do you make them oversize, undersized, or exact? Can a person make a spring swage for square or retangular stock? I'm figuring the square would have to be so you had a point straight up and one straight down. The rectagular one is for a 1/4x3/4 size of stock. I have a project that I'll need lots of stock of this size to do it. Is there a formula to figure what size of round to use to make a square of a certian size. I figure go by the weight per foot and match them kinda close. I also figure that you'll only get close no mater how you do it. I want to make my own stock, 1. to save money (special order at my supplier), 2. to use up a bunch of misc stock (read as good scrap), 3. to make the items look a little bit more "worked" and have more "character". Let me know what you all think. Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted July 23, 2005 Share Posted July 23, 2005 Are you trying to be extremely precise in the final measurement of the forged piece - i.e., do you envision a 1/2 swage to produce an exact .500 plus or minus .005? It can be done but I'm not sure you need or want that. I will describe how I make top and bottom swages for round stock to produce something pretty close to size - others will chime in. Take two blocks, clamp a business card between them and drill with the desired size (I'll use 1/2" in this example). Afterwards, the halves will be about .020 under because of the card but now you need to take a die grinder and greatly relieve the edges of the hole. If this is not done, you will get a lot of pinched material and cold shuts. Only about 20% of each side of the hole channel does the work (top and bottom) - the rest is removed. When done, the hole will be oval, maybe 3/4" wide. This will forge to a size that can be threaded with a 1/2" die. I have never needed anything closer but if you do, then I would make a set of "kiss blocks" to get to final size. These have a "U" bottom and either no top (power hammer die is the top piece) or a spring loaded flat top. You start on the large side and then grind off the 'legs' of the U until you get to the right size. The piece is rolled between the flat surfaces and "kissed" as it's turned. Square can also be done - it's a set of V-blocks and the corners need to be relieved like the round. I would do rectangles with kiss blocks. On making square into round and vice versa, I start with the next 1/8" size larger but do the calculation for a specific size if you need it exact. For example, 5/8" round is .31 in cross section, 1/2" square is .25. I hope you have a power hammer... :shock: Quote Link to comment Share on other sites More sharing options...
meco3hp Posted July 23, 2005 Author Share Posted July 23, 2005 Hello, Nope, no power hammer, but I do have a 14yr old nephew :wink: I'm not in a real big hurry just yet. I'm just making some tools for a couple of projects and figured I'd make some other ones while I was at it. If I can get an accuracy that is within a 1/16th I'll be very happy! No space shuttle parts for me! :mrgreen: Quote Link to comment Share on other sites More sharing options...
Glenn Posted July 23, 2005 Share Posted July 23, 2005 The rectagular one is for a 1/4x3/4 size of stock. I have a project that I'll need lots of stock of this size to do it. Why not go to the steel yard and order that size stock? I needed that size and they ordered it and it came in with thier next shipment. Is there a formula to figure what size of round to use to make a square of a certian size. When a blacksmith changes the shape of metal, he is changing the cross section but not the volumn. Area of a circle = 3.1416 times the radius squared Area of a square = width times the height To get a 1" wide by 1" tall = 1 square inch. 1-1/8" circle has a area of 0.09940 1-3/16" circle has an area of 1.1075 1-1/4" circle has an area of 1.2272 This does now take into account any loss due to scale etc. Numbers and formula from the 12th ed Machinery's Handbook When in doubt, go get the kids play-do or modeling clay. Others may have a better hands on explaination and I would certainly like to hear a "rule of thumb" on this one. Quote Link to comment Share on other sites More sharing options...
meco3hp Posted July 23, 2005 Author Share Posted July 23, 2005 Glenn, The main reason is my supplier calls it a "special order" because that isn't a normal size that they keep in house, hence a higher price. I know from working for them at one time that this is total bs, but there isn't much I can do about it. Also I'm working on a small budget, so I have to make do with what I can. I'll add that formula to my shop notebook. (I hate taking any referance books to the shop, they get filthy) My shop notebook is a 3 ring binder with all of the pages in clear sleeves. Sleeves get dirty I just replace them. I keep a pocket note book to write quick notes on, then when I get cleaned up after the day is over I transcribe them to a big sheet and add that to the 3 ring binder. Quote Link to comment Share on other sites More sharing options...
Glenn Posted July 23, 2005 Share Posted July 23, 2005 There is more than one way to skin a cat - just remember that you want a skinned cat when your finished. 1/4x3/4 size of stock - Let's see * That is 1/4 by 1-1/2 cut in half the easy way (NOT 1/2 by 3/4 cut in half - what I am calling the hard way :wink: ) * Buy a sheet of 1/4" plate and have them shear it into 3/4" strips. * Buy a sheet of 1/4" plate and have them water jet it into 3/4" strips. * Buy a sheet of 1/4" plate and have them plasma cut it into 3/4" strips. * Buy a sheet of 1/4" plate and have them laser cut it into 3/4" strips. * Call other companies that order steel from the supplier and see if you can add your order to theirs. Chances are the big boys get a discount that will offset the special order charges. Heating and beating is fun for the first couple of feet then the other options start looking better. The special order may still be the way to go depending on the length of stock needed. Run the cost of the special order against the labor and time of the other methods. Anyone have any better ideas? Quote Link to comment Share on other sites More sharing options...
meco3hp Posted July 23, 2005 Author Share Posted July 23, 2005 Hello, I never thought about going with the sheets of 1/4". thats a thought worth looking into. Comparing cost to time and labor is a very legitament idea, but right now I have more time than money. I guess I can look at this as good practice and keeping my self busy until things get moving faster. I hate the idea of working my self to death but I'm having to hurry up and wait on Uncle Sam for my business loan, so I'm going to stay busy! Thanks for the ideas! Quote Link to comment Share on other sites More sharing options...
irnsrgn Posted July 23, 2005 Share Posted July 23, 2005 Jr's rule of thumb for calculating shape changes. Most everyone has one of those handy little books the steel companies put out with sizes, weight per foot and weight per 20 ft. Round to Square, look up the weight per foot of the square you desire, look in the round section till you find a round whose weight per foot is just a little more. for square to round just reverse . If you have some scrap round and want to know what size square it will make, look up the round weight and then go look in the square section to find one that is a little less than the round is per ft. my2 Quote Link to comment Share on other sites More sharing options...
Ed Thomas Posted July 23, 2005 Share Posted July 23, 2005 Whenever you can, it is a good idea to reforge stock anyway. It removes the mill scale, dimensions things they way you want, and leaves the metal with a much warmer texture. There are still a few issues: When you forge, of course the steel doesn't all move in cross section. Depending on your hammer control, it could move just as much lengthwise. So you need to take some pieces and see what happens as you learn to reforge it. It is not cheaper to reforge in volume. A smith only does that to own the metal. The time and fuel will cost you more than getting the right dimension. There really isn't much need for a square swage, which is why they are so rare. The reason for this is that the most effective way to draw down material is in rectangular cross-section anyway. So all you have to do is learn to forge consistently. Cut some different thickness of notches in a piece of metal. Use that as a quick gage as you forge along. The best way to make round swages is to drive the size stock into the hot dies. If it is a spring swage, make up the blank, heat it, and hammer it over the round stock. This provides a much softer, more radiused die that won't chew up your piece as easily as a drilled hole. Details upon request. Quote Link to comment Share on other sites More sharing options...
meco3hp Posted July 24, 2005 Author Share Posted July 24, 2005 irnsrgn, That was one idea that I thought would be a good way to get a quick, rough idea of what would convert to something else. Ed, I like to see things that are made of "re-forged" metal! I think it has a more hand-made look to it, within reason of course. :mrgreen: Something thats made of mill stock looks too perfect to me. I like character in my things, almost to slight imperfections. Like I tell people, "Nothing's perfect". Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted July 24, 2005 Share Posted July 24, 2005 Try taking a piece of square, heat, then gently knock down all corners with the hammer and finally planish the flat surfaces at a red heat. When you are done, it should still be close to original size but the corners are gone and the flats have light texture. After removing the loose scale, take some 220-320 grit cloth and scrub the piece using your fingers to hold the paper (not a block). The high spots will shine and the low ones will remain dark. Makes for an interesting finish and it looks hand wrought (which it is... :wink: ) Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted July 25, 2005 Share Posted July 25, 2005 It's fairly simple to make a set of "stops" for a power hammer that lets you bring metal down to the correct size fairly fast and easily. Exp for a hammer with flat dies: take a piece of cold rolled the correct dimension and bend it in a "U" shape; then bend the base of the U 90 deg so it can be clamped to the side of the die leaving the two legs going across the top of the die with a clear gap between them. Now heat up your oversized piece and run through the gap til the top die is tapping the "stops" and you will have sq stock of your desired size Thomas Quote Link to comment Share on other sites More sharing options...
Ed Thomas Posted July 25, 2005 Share Posted July 25, 2005 Thomas: He already said he didn't have a power hammer. :? However, your concept works with a hardie tool on an anvil. Just weld pieces of metal on a plate with a shank for your hardie hole. There is a lot of energy loss this way, so it's better to get your stock close by regular forging and use this for final tuning. Just a quick and dirty bottom swage, in other words. I've never resorted to this for dimensioning, but have fabricated tools like that to swage collars and odd shaped railing. Quote Link to comment Share on other sites More sharing options...
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