View Full Version : Noob needs some help with a Bridgeport

Geoff Keyes
01-28-2008, 12:20 PM
Hi folks,

I am a Bladesmith (ABS Journeyman) and Blacksmith. As anyone will tell you, I am not a machinist, but I do have some machine tools, which I try not to abuse too badly.

I have a Bridgeport M-head, round ram, mated to a Clausing knee mill frame. When I bought it I didn't know enough to ask the owner what kind of tooling it used. Someone told me that it used R8 tooling, which is not the case. So the question is, what is it? I'm pretty sure that it is not B-3 (thank the metal gods), but the dimensions listed on one of the Bridgeport sites do not match the collets I have.

The collets are 0.543 inch at the base 0.700 at the head. Internal threads (don't have a thread gauge, sorry) on the base. 2.713 long, with three slots ending in a 0.190 hole at the end of each slot. The collets say "Neal Skokie" on the base end. There is a turned shoulder 1.053 up from the base end.

So what are they, where can I get tooling? Anything with a .500 +/- shank will fit. I'd like to get a drill chuck, I understand that a machine of this size won't be good for face milling, so I'm going to have to find another way to do that.

Thanks for you help,

Geoff Keyes
5 Elements Forge
Duvall Wa 98019

Rusty Marlin
01-28-2008, 12:29 PM
BRIDGEPORT MILLING MACHINE PARTS, motors, pc boards, new & used, mill & lathe tooling. (203) 882-0575 8am - 5pm Mike. Milford, CT

the collets you are looking for are a #7B&S taper IIRC, could be wrong so I hope somebody that KNOWS for sure chimes in.

Ian B
01-28-2008, 12:34 PM
I think Rusty's right - you can find dimensions of the B&S 7 here:



Optics Curmudgeon
01-28-2008, 01:02 PM
Lots of M heads had #2 Morse taper, very similar in dimensions.


01-28-2008, 01:04 PM
It's either B&S #7 or Morse #2. Both size collets are fairly readily available, so it shouldn't be a problem.

If you don't have one, request a copy of the MSC catalog www.mscdirect.com . It's free, weighs about 12 pounds, and is mind-boggling.

For a drill chuck, you can either get one with an appropriate spindle taper shank, or get one with a 1/2" straight shank and hold it in a 1/2" collet.

Clausing sold a bunch of their milling machines with Bridgeport heads. You might find more information at www.lathes.co.uk