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I Forge Iron

tapered threads?

paul hooper

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You can make tapered threads traditionally. 1) By making tapered swages for the various sizes, which involves making a rounded chisel, and cut the threads into the swage, top and bottom, making sure they line up, then forging the taper on hook etc., place in bottom swage, line up top swage and tap, then clean up with three cornered, or tapered file.
Sounds like a lot of work, but If you are going to make a lot of items, that's the way to go.
2) Forge your taper on item and cut threads with three cornered or tapered file.

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From the appearence of the threads I've often though the were cut after the taper was made. However they usually appear rather crude comapired to machine threads. More like the cut threads in old wood screws.
Have you looked in the MSC catalogue. They have nearly every commercialy thread die availabe

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I believe that most lag screws and wood screws are roll threaded after being cold headed. In the olden days, a "screw Machine" was designed to make guess what? Wood screws. These have multispindles and perform multiple operations all at the same time. These would most likey use an expanding chasing head just like making male tapered pipe threads, just different taper and pitch.
Neither of these two processes lend themselves to home shop use. A screw machine is profitable to tool up for runs of many thousands to millions of a part. Same for cold headers with roll threaders.

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Ah, the modern world we live in! Blacksmiths invented the screw thread! Many old lag bolts had twisted threads. I think we should see who can make the best all forged thread. You can start with a symmetrical form you know, doesn't matter if it has two threads. I have forged threads in a swage before, you have to have just the right diameter to start because if it has to extrude it wipes out the thread and you have to screw it in and out as you turn it. C'mon you guys, go experiment!

If you look at most large lags, they don't have threads on the point, just a point.

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