Need the cores, not the holes

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Hey.I have to drill some cores out of sheet steel.  Funny thing is I don't want the hole in the sheet, I need the "core" / circle.  So twist drill is out.I need the circles to be small... about 3/8ths inch.  If there are any suggestions I would be grateful.
Reply:Hole saw.
Reply:Would you be better off cutting 3/8" diameter rod?
Reply:annular cutters will work the best"Liberalism is a mental disorder" Dr. Savage
Reply:Originally Posted by backhoeHole saw.
Reply:What gauge? What about punching them? I'd look for a Roper Whitney or Pexto lever press. http://roperwhitney.com/punching/punching.cfm The only issue is that the punch leaves a small dimple in the middle.Another option if you have a press is to use a Unipunch. They can be had on ebay and have a good assortment of dies. The Unipunch has a retainer ring that helps maintain the material without distortion and the punches don't require a point in the middle.[ame]http://www.youtube.com/watch?v=ZQuxN6K89xI[/ame]
Reply:It depends on how thick you need them.  I've punched holes in thin sheet using a hammer and a pin punch backed up with an end-grain hardwood block. Perfect hole and slug, but that was really thin stuff.  Someone with an iron worker and a punch could make you a bunch in slightly thicker stuff, and just might have a bucket full in their recycle bin."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Originally Posted by joshuabardwellI haven't seen a hole saw less than 3/4", although I suppose they probably exist as a specialty item.
Reply:I would thin slice some 3/8 round bar on a bandsaw, or go with what forhire said with the punch drops, I use them all the time at work.I hate being bi-polar it's awsomeMy Heroes Have Always Been Cowboys
Reply:*Rick V 1 Airco Heliwelder 3A/DDR3 CTC 70/90 amp Stick/Tig Inverters in Parallel1 Lincoln MIG PAK 151 Oxy-Acet
Reply:A punch would be the fastest, but you would need a decent size machine to punch 3/8 without distortion... the one above has a little dimple that starts the hole...plus it's dies are too small... or a large spot weld cutter might work also...Lincoln pro mig 180Lincoln Square Wave Tig 300/wp 20/home built water cooler Victor, Purox, Harris, O/A welding/cutting setupsVintage Craftsman drill pressVintage Craftsman/Atlas 12"x 36'' lathe7''x 12'' w/c band saw Everlast 140 st
Reply:where are you located?  How many do you need?  I have some 7/16" knockouts at 3/16 and 1/4 thick. maybe some 1/8 thick too.  Hole saw will be a pain to deal with unless it self ejects.  1/2" hole saw will get you the size hole you want.  Annular cutter will eject the metal, but still have a ridge to clean up.  Might be able to have them cut? Perhaps a machine/metal work shop that does much punching.  Punched holes may deformed with a center punch mark.
Reply:Hey Thrillofspeed,I don't know what gauge of steel you're cutting these discs from, but if it's not too thick you could try some of the disc cutting dies the jewelry sites are selling. Check out the one in the link below.http://www.pjtooljewelry.com/7pcmetaldisccutter-2.aspx
Reply:This thread is useless unless you specify dimensions (diameter, thickness and tolerance).  And material.Or at least tell us how many bushels of these you need so we can get excited about it.Last edited by Oldendum; 12-26-2012 at 06:55 PM."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Call Boker's  We used several special stampings at the helicopter company and Boker always could provide us with exactly what we needed.  May not be cheap but they produce and always had a quick turn time.http://www.bokers.com/precision_metal_stampings.aspRogerOld, Tired, and GRUMPYSalesman will call, Batteries not included, Assembly is required, and FREE ADVICE IS WORTH EXACTLY WHAT YOU PAY FOR IT!Dial Arc 250HFThunderbolt 225 AC/DCAssorted A/O torches
Reply:Originally Posted by weldermikeI would thin slice some 3/8 round bar on a bandsaw, or go with what forhire said with the punch drops, I use them all the time at work.
Reply:Wow!  Great suggestions.  Thank youI was fearful of telling you all the material.  It is actually flat "slices" of meteorite - an iron and nickel alloy.  As far as thickness the slabs are maybe 3 or 4 mm.The punch ideas will most likely be the most beneficial.  I don't mind a dimple in the center as these usually get drilled (twist style) to have a diamond or other precious stone mounted.I'm in NJ not far from Philadelphia so I can ask around at some machine shops.  I only need about 50 pieces.  I can post a photo of a finished piece to show you guys.  Thank you all very much.
Reply:thrillofspeed  -  What diameter, and when/where was the find?  -  Opus
Reply:I'm not sure, the slabs were purchased as part of a lot of material all slabs.  The slabs are about 3" oval.  If you'd like to see one let me know.  They are kind of cool.
Reply:thrillofspeedThickness: 3mm is 1/8" minus, and 4mm is 9/32' +. What diameter, and number count do you want to produce from your blanks?  How much edge margin can you waste? Do you have usage/design for the interstitial material?  Meteoric Nickel/Iron typically Mohs at 5 +/-.Drop and hardness drive the considerations for a blanking process choice; answer what you can, there are still more options.Opus
Reply:I would take it to a machine shop someone who has a cnc turret punch and ask them to punch your discs for you, with Turret punch tooling you get no dimples and they could easily punch 100's out for you in a matter of minutes, Just have a chat with the foreman, take him a pack of beers and Job Done
Reply:Originally Posted by OPUS FERROthrillofspeedDrop and hardness drive the considerations for a blanking process choice; answer what you can, there are still more options.Opus
Reply:Opus Ferro -- waste is not super advantageous of course, I'd like to maximize my usable material.  However some waste is always expected.  The annular drill bit seemed like a reasonable option.The material is relatively homogenous, at least to the naked eye.  I have not examined it with anything more than a 10x loupe.Gerry1964 -- The CNC punch might also be available, I know some Union Welders who are a great bunch of guys who might be able to steer me toward someone with a punch.  Thanks for all the ideas! Attached ImagesLast edited by thrillofspeed; 12-31-2012 at 10:18 AM.Reason: attach photo
Reply:How about a water jet?  They could program the machine to cut so there would be little waste between the holes.