Countersink problems in Aluminium

I have recently been having problems countersinking in 1/16th inch aluminum plate.
I am using a drill press. Instead of a nice round hole, I am getting a sort
of hexagon shape.
I am using five edge countersink made by the Severance company.
I do not remember this sort of thing happening before.
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david.







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Try a single hole type countersink

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As Tom said, a single hole countersink may help. I much prefer them to the multiblade countersinks. I also find countersinks prone to chatter unless the speed is right. I usually end up slowing the speed when I get buggered up holes. Could the countersink be dull?
Peter
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Peter Grey wrote:

What's a single hole cutter? Is this a cutter with a single cutting flute ??
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Peter
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Peter Grey wrote:

Thanks Peter
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Peter Grey wrote:

single hole single hole single hole single hole
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Single flute?

Way slow, and use soap or paraffin to lubricate the countersink.
LLoyd
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Lower the spindle speed.
Jim
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jim rozen wrote:

Or increase the feed. Or use a single flute cutter.
Or use a piloted countersink.
John Martin
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Thank you all for your suggestions. Will slow down, keep the pressure up and see if that improves before purchasing a single flute style.

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