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I Forge Iron

Die Cutting

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I am making a sheering die for my toggle press to knock out simple squares.  This particular die will cut 1" and 5/8" squares.  I'm using a piece of leaf spring 3" wide and 3/8" thick.  I've not had it tested yet, but my guess is that it's plain carbon between 80 and 90 points.  I've used springs before for sheering dies similar to this, but I have to say I prefer 5160, which is typically used in the thicker springs--1" and up.  Since this is going to be a hot operation, the alloy is not as critical as it would be for cold.  As we all know, the difference in hardness is more from heat than anything else; and in my experience, the biggest enemy is abrasion from the scale, not distortion from power.  Spring works for that.  It's easy to machine and it's free, both of which let me feel more willing to experiment than with a 50 dollar slab of D2 that's a tool chewer.  

The first thing is to lay out the holes in their approximate location.  Nothing really precise about this other than the corner marks to hold it to the bridge. 


Then it's drilled. 



The spring was a tad wide to fit into the die holder, so I ground the edge. 



Then I put it in its die holder and mounted that in the Garvin die slotter to rough cut the hole square.  For anyone who doesn't know what a die slotter is, it's like a shaper, only vertical.  The Garvin's ram can be tilted too, to get the relief for the die.  It uses a single point tool like a lathe's. It has a rotary table and X Y Z.  



One corner's cut at a time; it's rotated 90º and then the next is cut, until they're all done.



It's pretty rough inside yet, so I take it to the die filer.  This also has a table which tilts for relief.


It took about twenty minutes to smooth it.


Next is to make the punch, but that will be another day.  That's when it'll get its final sizing and fit.  For now, it's only approximate.  Finally, it will be heat treated and surface ground, top and bottom.  


I hope you enjoyed this.  Comments and questions are welcome.







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6 hours ago, Sanderson Iron said:

When my tenth birthday came along, people asked me what I liked--what I was interested in--like grown ups do to kids, hoping for the best.  I told them, "Ropes and pulleys."  Nobody understood.  That was just weird.  You guys would have gotten it.  

Hehe! It's okay to be weird ;) 

That's a wonderful shop, real pleasure to see! Thanks for sharing.


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  • 4 weeks later...

Wow.  I can't believe I started this thread back in February and still haven't finished.  Dies do take awhile, but this is ridiculous.  Hopefully nobody here thinks I've been working just on this.  Ha ha! 

Anyway, the next step was to cut the small, 5/8" round hole to 5/8" square.  It was slotted and die filed just like the larger hole.  I rough finished both holes knowing that they'd be final fitted to the punches later.  The cutters for the slotter are really easy to grind--even easier than a lathe's, since its action is all on the end.  It doesn't even need any back relief.  I made this one out of a 3/8" HSS lathe bit.  No picture of that.  (Sorry.)  


Next is to make the punch.  I turned a blank on the lathe.  This is D2 for those who care.  A friend brought me a piece a week ago.  The body's 1 1/2" round. 


There needs to be nice clearance at the base of the face when you're cutting the sides by hand--otherwise you can't push a file past the image.  Blind hole filing isn't very successful.  So that's why it's undercut behind the face.  Make sense?  


Below you can see it next to two other punches I cut a few years ago. I hope you can see what I mean about the need for space behind the image.  You can see on the smaller die where I could have gone a little smaller, since there's a file or graver mark where I hit the neck.  


So then I popped it up in the vertical mill and cut the face square.  There's no relief on the punch; it's all in the die.  This is an easy punch to cut--no hand cutting and no need for a dividing head.  Just happy square.  


Then I cut the other flats.  This old mill (1920's?) has no calibrations, so I use a test indicator.  Works better actually, because you're not trying to compensate for backlash or lead wear.  It measures what the table actually travels rather than what the table is told to travel.  


And whoopee! It looks right.  Must be I did my math right. (Ugh--math and art!)


I cut it to the same dimensions as the die's hole, so it took very little hand filing of the die to get it to fit.  However, because it's hand fitted, and because I'm me, making art, and don't care about precise size, it fits only one way, so there are indexing marks so I know how to position it.  


Then I surface ground the die.  I sure like that surface grinder.  I like any machine I can go away and let do its thing while I do my thing.  (Need to figure that out for a power hammer.  Ooo, scary! )  I once had a surface grinder without any power feed, and I tell you, that was one boring thing to stand and make happen.  This brute takes power, but it's worth the extra fuel.  Of course, part of it's the 110 v DC chuck and the dynamo.  


And she's shiny now.  How perty.  


I'll be making the small punch later this week, and after it's fitted, they're all off to the heat treating place where they know about that kind of thing.    

Hope you're enjoying the picture show.  




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1 hour ago, John in Oly, WA said:

Now that's my kind of machining. Most All of my work is the same.

Ha ha!  We are blacksmiths, after all (at least that's my goal).  It just needs to look square, and being .005" off on the square (which I was) won't be remotely noticeable, but that's enough to make it want to go in one way.  

Still, you'd think I could make a square square, wouldn't you?  Sheesh. :) It's a happy square though.  

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Thank you, Donniev and K A Willey.  

I finished the smaller punch and its mating die yesterday.  I redeemed myself!  It fits in any rotation!  Nothing quite like a little concentration. :)  I have one other set of dies to finish today so I can send them all to the heat treat tomorrow.  Finally!  I've been making dies and shoes for weeks.  I have several more to make, but I just might take a break for awhile and move some hot metal around just to ease the blacksmithy side of my brain.   



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Just getting to this thread now -- very cool! I love your shop, and I totally get the "ropes and pulleys" thing. I got rope as presents a couple of times.

How thick material can a slot cutter and die filer cut? I see square holes, and I think hardy holes in striking anvils....

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3 minutes ago, JHCC said:

Just getting to this thread now -- very cool! I love your shop, and I totally get the "ropes and pulleys" thing. I got rope as presents a couple of times.

How thick material can a slot cutter and die filer cut? I see square holes, and I think hardy holes in striking anvils....

They're limited by the stroke.  I think the Garvin die slotter has a 2 1/2" fixed stroke, but don't remember for sure.  The die filer's even less, though it's adjustable.  They're both for 1" and less, I supposed, and even that'd be pretty thick--up to 5/8" is more like it.  For cutting deeper unround holes, a shaper's what I'd suggest.  That's one of the most all-around versatile machines for blacksmiths.  I don't think a blacksmith should be without one--right up there on the list with a drill press.  A shaper will do everything a mill will do except bore round holes (which can be done on a drill press with a boring head) and it'll do a lot more that a mill cannot. 




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