Swage block

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I have been working on some blacksmithing projects, which include a lot of surface forming, and it has all been over a standard anvil. The carbon steel skillet that I recently started is a project that I have found difficult to form perfectly without a swage block or the right sized mold. In this regard I have designed a swage block on fusion 360 and plan to have it milled by a friend of mine. The only problem is I need to find the stock for this project, the size is one square foot and three inches thick. The price of metal has really escalated and I don't really want to spend $400 on this project. I do have some 1" steel plate that is the right size for the swage block, only I would have to stack three pieces together. What would be the best way to fuse three stacked 1" mild steel plates? I have thought of forge welding them with my triple burner propane forge, but I don't think it would get hot enough to forge weld so much metal. Would  a series of slot welds over  the top down to the bottom plate, and four but welds around the perimeter be a  good way to fuse the plates evenly without them warping, to create a block solid enough to mill?
Reply:I have no idea what a swage block is, but................  I laminate plate quite a bit.  If you're making a round form, drill the 3 plates, cut pins on the lathe for a press fit, cut them to length so that you can plug weld them in once they've been pressed through the 3 pieces.  This allows you to machine around the edges without running afoul of any perimeter welds.  I have pics somewhere if I can find them.
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  Both sides are plug welded.The 4 pins hold the whole thing together extremely rigid.  The more pins, the more rigidity.  The built in error in all the drilled holes grabs the pins like a vise in addition to the press fit.  This assembly was machined with no problems.............no movement, no warpage, and the finished part works very well.  It's a very tough assembly.
Reply:The part underwent significant stress during machining, and did not develop a parting line.  The halves are almost undiscernible.

There's absolutely, in most cases, no need to buy expensive solid stock when lamination will do nicely.  It's not for everything you make, but it certainly fills a gap.Last edited by farmersammm; 2 Hours Ago at 01:00 AM.Reason: added last sentence
Reply:I looked at some pics of swage blocks to actually see what they were.  Do a perimeter weld if the forms you want are in the middle.  Do the pins/plugs if the forms you want are on the outside.
Reply:Hopefully some of the more experienced blacksmiths will wade in on this one . I can't help but think there are better techniques with your traditional anvil that would be easier than building a form/swage to fit the project. It sounds like you already have enough experience to know that a laminated block is not going to have the rebound that a solid block will, but there's no reason why it can't work. If you were going to go ahead with it, I think Sam has a good plan. Assuming you will be machining out a lot of the center, you could pin it along the outside edges. Another method that would work with the 3 layers of laminate would be to drill the 2 outside pieces and plug weld them to the center one, and bevel the connecting edges and weld them along the perimeter. You are working with a lot of metal, and should probably use your forge to pre-heat it before welding and cool it slowly.The harder you fall, the higher you bounce...250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:Ah yes, that makes sense, the pins would hold it together with high friction along with the fusion and shrinkage of the plug welds. I would need to use a heavy hammer to install the pins, as I do not have a press. what is the rating of the press you would need to press in the pins with enough friction, would a 1 ton arbor press work?
Reply:I have many smaller swages on the bottom of the block, but the most important one is the 10" concave cavity on the top of the block.After welding the block I would probably need to anneal it in the forge to allow the mill to machine the outside for the outer side swages.Last edited by ChrisCramer; 2 Hours Ago at 01:28 AM.
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Originally Posted by ChrisCramer

Ah yes, that makes sense, the pins would hold it together with high friction along with the fusion and shrinkage of the plug welds. I would need to use a heavy hammer to install the pins, as I do not have a press. what is the rating of the press you would need to press in the pins with enough friction, would a 1 ton arbor press work?
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Originally Posted by ChrisCramer

I have many smaller swages on one side of the block, but the most important one is the 10" concave cavity on the opposite side of the block.After welding the block I would probably need to anneal it in the forge to alow the mill to machine the outside for the outer swages.
Reply:I don't think I would need to use an alloy for this that could be hardened so much more. I wouldn't be forging any alloyed metal other than stainless sheet metal over the swage block. All of my wrought iron is mild steel, and there are many blacksmiths that just use a carved stump to shape things like a skillet. It definitely makes sense that a laminated block would not have as much rebound as a solid block, but this is only my first swage block that could be improved in the future.
Reply:It's a good project to get your feet wet.  The learning curve isn't very steep.  Make sure to bevel your edges if you're going for a perimeter weld.  The bevel gives adequate penetration.
Reply:I envision you dishing this out so you can for the skillet?  The feather edge might become an issue... It might break.  How hot do they get during work?  I could see possibly separating layers since they taper to thin.  How close will your plates fit? That may improve rebound if they could be flattened before welding.