What is the best thing to use to cut E core laminations from electrical steel sheet?

Discussion in 'The Projects Forum' started by electronice123, Jul 29, 2009.

  1. electronice123

    Thread Starter Senior Member

    Oct 10, 2008
    I have some electrical steel I need cut into E and I pieces. The Electrical steel is pretty thin M4 grade (.011") THK. The problem is I don't want to spend a crapload of money for laser cutting or stamping.

    What is the best thing to use to cut E core laminations from electrical steel sheet?

    I have been told to use a guilotine paper cutter?

    Has anyone here cut there own cores, any tips you guys can give me will be greatly appreciated.
  2. someonesdad

    Senior Member

    Jul 7, 2009
    A foot shear would be the fastest if you can get your hands on one. But you can't cut the internal parts of the E unless you have a notcher of the right size. Neither of these are cheap pieces of equipment.

    But 0.011" thick steel is pretty thin material. I've got a big roll of some 0.015" galvanized steel and I just cut it with my tin snips -- it's pretty much just like cutting paper with scissors, although of course it takes more hand strength. I don't mean the compound cutting types, I mean the big cast aluminum ones with non-serrated steel blades bolted into them.

    You can try the paper cutter, but you'd get a .45 slug through the kneecap if I caught you doing it with my paper cutter. :)
  3. jpanhalt


    Jan 18, 2008
    The inside corners will be a bear to cut with anything short of using a punch and die.

    How many times do you need to do this? If it is just once, then consider a "nibbler." A nibbler is just a small square or rectangular punch and die. They are often hand operated, like paper punches, but can be powered too. Check metal working and aircraft supply places.

  4. DickCappels


    Aug 21, 2008
    11 mills of steel can be pretty hard to cut. And how many layers? Much better if you can buy the pieces pre-cut.

    Caution: The rough edges hurting your hands or the insulation on wires as the exit the bobbin.
  5. Externet

    AAC Fanatic!

    Nov 29, 2005
    I would say looking for a transformer that can donate its iron E + I core sheets at the correct size is by far the best option, as without specialized cutting equipment and dies, the result will never be even.
  6. someonesdad

    Senior Member

    Jul 7, 2009
    You don't say how many pieces you need nor give their sizes. I disagree with Dick; 0.011 inch thick low carbon steel is pretty easy to cut with hand tin snips. jpanhalt is correct that the interior portions of the E will be the hardest to cut. If they're small, the hand-held nibbler is the way to go. If they're big enough, you can use compound leverage sheet metal cutters to make the cut, but you won't get nice edges as if they were stamped.

    Your best choice may be to go to a sheet metal or HVAC shop and ask them for a quote. They'll be able to do it much faster than you will.

    If you go to a sheet metal shop, you may just be able to get the hard task done by them: cutting the square internal portion of the E. They can stick a square punch and die in their punch and punch those pieces out for you. You can do the rest with some hand-held shears.

    Another approach for the E pieces is to cut them to their rectangular size, then stack them alltogether between two 1/4" steel plates, clamp them tightly with some C clamps, then cut out the needed E shape with a 32 teeth per inch hacksaw blade grinder, chopsaw, etc. There will likely be some hammer flattening and filing to final size of each piece later.

    If you have access to a metal cutting bandsaw with a very fine-tooth blade, you could cut out each piece by hand. Make a zero clearance insert for the table first.

    A welder who's really good with a cutting torch might also be able to get this stack near to the final size. You'd finish it up with filing or grinding.

    You could make the long parts of the E cuts with the tin snips, then use a diamond or abrasive blade in a Dremel tool to make the short cuts. This would probably go pretty fast and might be the most pragmatic way to get what you want. You'd be able to get sharp corners. I often do this kind of cutting with my circular saw on plywood. In fact, after thinking things through, this is the method I would try first if I needed to do what you want to do and it was less than, say, 50 pieces. It would certainly be the cheapest way if you have the requisite tools.
  7. electronice123

    Thread Starter Senior Member

    Oct 10, 2008
    Thanks everyone for the help,

    To give more info:

    There will be 75 Pieces of each E & I.

    The pieces are 3.5" in width X 2.875" in height, with the center leg being .75" wide, the outer legs are .375" wide, and the cutout sections are 1" in width.