Hole saw bit steel?

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d.weglarz13

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Jun 4, 2008
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I know someone here knows the answer to this one! Hey guys I have a weird question so please forgive me if this is in the wrong section and will the mods please move it...I have a project for school, and am hoping I can figure out an easy way to go about filing a certain steel. And, I figured I would ask you guys because you have given me great advice in the past and you guys know the most about saw steels, and the like.
I need to choose a steel, to make a punch out of. It will be a circle punch press, and the diameter of the hole needs to be 3.25". Now, at my local hardware stores, they sell this diameter hole SAW bits, and Im wondering if I can just go ahead and file the teeth down to a flat surface? I am only punching through plastic sheets no thicker than a few sheets of paper, but i need to do thousands of them. I could always have the option to resharpen the ring punch if I need also, thus why I am wondering if one steel is better than the next as I need to keep the ring sharp as to not punch sloppy holes. Now, is this possible? or would I need to somehow soften the steel then harden it? Or, is there a better way to go about this? But, I am working with a very small(almost nonexistent) budget, and would like to do this myself if possible. This is my first time building something like this, so any and all help would be greatly appreciated. So, thanks for your patience everyone, but could someone possible point me in the right direction? any links or ideas?
Is there a certain type of steel that i could use for this just by filing a pipe or hole saw bit into a sharp edge? Then of course, I would secure this to a vertical movement application of some sort to work as the press, much like a drill press. So, again thanks for your patience and help in advance.
Dave
 
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Buy the hole saw and cut a hole through two layers of 1/2" plywood. These will be your dies.
Grind the teeth off on a bench grinder or belt sander Don't overheat the metal) and then lap them smooth and flat on some 120 grit wet-or-dry sandpaper laid flat on a flat surface. Take the surface up to 400 grit when you get it totally flat. Use a granite surface plate if you have one available. This is your punch. The smoother and flatter the edge, the better it will punch. The outer edge must make a sharp angle, as close to 90 degrees as possible. Now, use a rotary stone in a dremmel or similar tool and taper from the inside edge toward the outside edge, making a sharp edge. This is the cutting edge.
Put the punch in the holes of the two plywood pieces, thus aligning them. Slip some strops of 1/8" wood between them to space them apart, and glue a strip of 1/8" thick wood between the two die pieces along the back edge. This will leave a space that you can slide the plastic in and punch it.

Slide several sheets of the plastic between the dies, and cut down with the punch. A drill press ( not running) will probably be fine for applying the pressing force.
 
Bladsmth has it down mostly. You would basically be making a steel rule die. here is a pic of one.

Steel-rule_die_2.png


A good baking material would be a semi hard plastic or polyurethane.

A drill press ( not running) will probably be fine for applying the pressing force.
Click to expand...

This will work as long as you set the "drill depth". meaning you have a way to set the drill to stop at a certain point.

EDIT: I've been drinking a bit today, and I just realized you do not need a stop. you will not be able to pull thru plywood. Just have replacement slabs ready when you start marking up the ones you are using.
 
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Oh wow. that was amazingly fast. Thanks I really appreciate it. But, would plywood be fine to use as the die? I mean, I can do it this way, and not have to use something sharp like metal for the die also?
And, the plastic is very thin, but has a lip on it, much like a coffee cover lid like one you would get from 7-11. So, the outside edge of the plastic will be about 1/8" thick. So, I suppose leaving that 1/8" space you were talking about would be close to perfect.
All in all, it would be equal to putting a hole in a coffee cover, leaving only about 1/2" ring along the outer edge of the cover,(only a bit larger diameter than a coffee cover but the idea is the same).
I wouldn't mind toying with the idea of a design like in the pic above also. Is there a certain steel that I would need to use for that?
Again, thanks.
Dave
 
Yes, if possible a metal die would be better, but making one in wood will be simpler. A piece of hard and smooth material, like Corian would also be a better choice than plywood. Check with a cabinet shop or place that does kitchen counters and they will give you a scrap piece.

You had said there was almost a zero budget, so I was going with cheap vs best. If the hole saw is a metal cutting saw ,you could cut the bottom die ( the top one is for alignment ) in 1/4" steel. If the hole saw is one for cutting door lock openings in wood, it won't cut the metal plate. It will cut the Corian, though.

You can customize the slot between the upper and lower die to conform to your material. The 1/8" was for basic explanation. The spacer strips can be placed as needed to make the die assembly hold up. On re-thinking my post, I would suggest placing a spacer strip on opposite sides to allow the plastic to be inserted from the front, punched, and pushed out the back by the next piece inserted. This would make the die assembly more rigid,too.

There are lots of ways to flatten the saw edge, and make the die, but I figure that you can devise those changes to fit your need and ability.

BTW, save the cut out circles of wood and place them in the punch to fill the hole up to nearly flush with the edge. Otherwise, the disks may get pushed up into the punch instead of dropping out of the bottom hole of the die.
 
Wow Stacy, I really appreciate you taking the time to help me out here. It is exactly what I was thinking but with more details I haven't thought about. This will help me a lot. If you think of anything else, feel free to throw it in! Thanks again.
Dave
 
Yes. this is something very similar to what i need. thanks very much.
If i were to try and make my own shape(not a circle, for instance), what type of steel could I use for this? Im guessing I wouldn't have to harden it?
Also, being that it is very thin plastic, would the cover be pushed down into the die instead of cutting it clean? I mean, is this the best way to do this? Or is it easier for this application if I use a wood block on the bottom, and just the circle punch on top, in order to not push and crumble the plastic lid I am cutting. I am just curious to what you guys think. If the punch and die is the best, I will go with that. Thanks again for everything.
Dave

Oh, and that link was great! Any other ones similar to this(or any sites with info like this), feel free throw it at me!
You guys are the best.
 
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Okay, and Im thinking more about a custom shape punch and die now, much like the one in the picture above....So, any ideas on what steel to start with? Again, thanks.
Dave
 
They are called Steel Rule dies for a reason.

Steel_ruler_closeup.jpg


What are you trying to do now? If you include a sketch I can help out a bit more.
 
Okay, so I know its been over a week, but I was just so bogged down with work and haven't had any time to work on my project.
So, I was having trouble opening my Photoshop, and thats the only program I have on this computer for drawing. So, Please excuse my desperate attempt at trying to draw freehand, but its the quickest thing for me right now.
This is what I ultimately need to do, if possible....
In the pic, you will the plastic circle that I already have. What I need to do is, take each circle and cut or punch out the design that I filled in in black. Like i said, I already have the circles, but need to punch out this "quadrant" design into many of these plastic circles. The material itself again, is pretty thin. I would say like a 8 or 10 mil plastic, or about the thickness of a plastic cover you would find on a coffee cover. And, i just need to punch that design into all of them.
Originally, I was going to do just a big circle, but this is really what i need to do within reason. And if it is possible to do what you guys call a steel rule die, how would I go about having a die like that AND a press(well, the bottom piece that allows the material to shear much like a hole puncher) made, and what should I ask for? I mean, if I could do it myself, but it seems that it would need to be for thousands of punches, so I assume I would need someone to help with that. But, again, the coffee cover type plastic lids that I am using are only about 5 inches in diameter, and the proportions of the drawings are pretty much exactly what i need. So, again, Im sorry for the delay, but here is a crumby drawing by me.
Any and all thoughts and suggestions are more than appreciated in advance, and also for everything so far. thanks
Dave
Sorry the pic is so big...
4b820e12.jpg
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And, again, money IS an issue, just thought Id throw that out there again. thanks guys
 
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I'll be straight forward about this.
First you wanted to punch simple circles. Now you want to punch a complex 8 segment pattern. Such a punch and die will cost several thousand dollars on the low end. The press to opperate it may cost as much to build.

What exactly are these plastic pieces going to do?
 
I agree it is getting much more complicated now.

If you wanted a few, I would say, just get the item waterjet cut.

thousands of these?


I agree more info would help.
 
Okay guys. I didn't mean to sound all over the place. This is for a school project, that's why I was thinking circles. Then, I got the idea I maybe able to put something like this to use for my own small business. Thus, why I was thinking about the segments. But, if there is really no way to do this or have the punch and die made like this with out spending thousands is dollars then I will just forget it. But thanks again for your opinions, I sure wish this wasn't so expensive.
Dave
 
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