Two main tapers BT40 and INT 40
Differences are INT 40 has a short parallel part on the top of the taper.
BT40 is just the taper, tapers are the same.
Then the water gets furter muddied with ISO 40, CAT 40 etc which are all the same taper and fitting as BT40 EXCEPT for the flange with the driving dogs.
On a manual machine this doesn't matter, the flange differences are for the toolchangers on CNC machines.
Pull studs are for the tool changers but screw in Without a pull stud the drawbar fit into the same hole. Draw bar is usually M16 on BT40's and the ilk. The older INT 40 with the nub on top is usually 5/8" whit
[edit] this keebord kant spel
Edited By John Stevenson on 02/02/2013 15:07:10