Hey, that's a start

I had heard those spot weld bits didn't last long.

I forgot to say, I made my own, using just a regular steel twist drill bit.

Use a 5/16 or 8mm which ever you prefer.

You sharpen it a different way to normal.
Removing the the steep angle, usually 118degrees for a regular twist drill and making it flat.
While still keeping the point in the centre to align the drill

I'll try take a picture of one for you.

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