BT40

I have been enjoying Jason’s post on the Bridgeport lust but decided to keep out of it. Although at one point I thought he might have had the opportunity to buy mine as I am looking at something slightly younger.

This brings me to the question I went to see one this week which was just a bit too bashed up even at the price. It was fitted with a BT40 spindle. Being used to R8 I this was a negative before I got out of the car as I have every adapter widget and gubbins you can get with an R8 taper.

If I had bought the mill I was obviously going to need a lot of BT40 tooling. So I did a bit if window shopping. But what it returned was BT40 ISO 40 DIN40 BT40 with pull studs BT40 without and so on. R8 is R8 anyone shine a light on the rest?

Jim

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

Thanks John seems like I am only in trouble if I have a ATC which I won’t as it’s a manual machine I am after.