The shank is electrically conducted to the metal workpiece through the chuck and table,
the LED lights up and the beeper sounds(only for 6566-3E),
when the ball touches the workpiece
Not suitable for rotary use. Hardened shank and contact ball
Hardened shank and contact ball

3M 28473, Roloc D/F Cool Running Disc Pad TR, 4 in x 5/8-11 Internal, FIN, 7000144107
Insize 6315, MICROMETER MEASURING FORCE DETECTOR, 6928640351143
3M 45179, Roloc Disc Pad TR, Medium 4 in 1/4-20 Internal, 7000045281
3M 45190, Disc Pad Hub, 4-1/2 in 5/8-11 Internal, 7000045659 