Identifying Bridgeport R8 Collets - Questions

Hello,

Yesterday I received what was sold as a set of Bridgeport brand collets. I have only looked at a few of them but most do not say Bridgeport on them. Some also have a a threaded insert for the drawbar instead of being solid. Did Bridgeport put their name on every R8 collet? Did they use threaded inserts instead of a solid body?

I suspect that I received a few Bridgeport manufactured collets and the rest are made by who knows.

Thank you in advance,

John

It has been years since I have seen an original Bridgeport collet. Both my manual mills have 30 Erickson spindles now. I think Bridgeport collets in the old days had inserts, the only solid ones I have ever seen were Hardinge. Relatively new collets should have Bridgeport or Hardinge logos on them somewhere.

All BP collets were marked as such. I've never seen an R-8 collet that did not have an insert. I don't know how you'd thin the walls on a small diameter collet without going in from the drawbar side. Without thinning the walls, the collet would be to stiff to work properly.
JR

It has been more than 30 years since I worked in another shop and had an R-8 collet in my hand, besides the set of Hardinge that went with the machine I sold.
Every one I saw besides Hardinge's had a bushing.
Hardinge 1/8 solid collets had the thinning done through the drawbar hole. would have liked to seen how they did it. I am guessing they did the thinning/counterboring before forming the threads. If you have never seen one it, would worth buying one to look at and try to figure out how they did it.
Over the last 40 years I have seen the changes Hardinge has done to their 5C collets, and can tell you what time period the different one come from. I thought Larry or some other old timer would be able to say whether BP ever made any with logos that could wear off or with no logo.

I just checked my set in my shop.
ALL the Bridgeport collets were only marked in the side with a chemical marking that can be removed easily.
There is no marking on the exposed end of the Bridgeport collets, all the other brands I have sen ARE marked on the exposed end.
All the R-8 collets I have seen do have inserts on the threaded end, but I know I have never seen all of them.

Bill

I have some genuine bridgeport collets and they all have inserts and all are/were labeled on the side. I was curious once and got them outin the sun and was able to see very faint logo on them with the angle and the light just right. The logos on mine were all in the same spot in relation to the keyway, cant remember if it is above or below. But look at one that you can read the logo on and the rest should have the logo in the same spot, saves trying to look all around them when you know exactly where to look.

car2 said:

From hardinge website: "All Hardinge R8 collets are a solid one piece design, hardened and spring tempered to assure accuracy and durability."

Click to expand...

I would just love to see how they do the ID thinning. That's only about a 3/8" hole to get through. One of the reasons that they are more expensive.

BTW, my R-8 collets are all chem etched. I would suspect now they use a laser marker. So fast and so accurate.
JR