As we were almost finishing the catalogue in 2009 we were introduced to these drill bits and have tried them.
They are truly staggering. An amazingly fast cut with no break-out (even on made acrylic or Dymondwood blanks) leaving a perfectly clean bore. 6” long overall, 4 1/2” drilling length.
We found they work best at a higher speed.
Take a look at the excellent two and a half minute youtube video. It shows it all and is very well presented.
;)
