Identify these collets?

[Mill Lee farm]

Ok. Believe it or not someone trashed this at the auction. Really nice little custom holder box and an assortment of collets.

99% of everything at this auction was vintage industrial woodworking….
Does anyone recognize this collet style? They don’t seem to have a taper and I haven’t measured them although their length varies.

 

[extropic]

They are type C collets, adaptors for holding the ID size tool in the OD size collet or tool holder.
For instance, if you have a 3/8" OD boring bar and you want to hold it in your 1" ID bar holder for your QCTP.
Same sort of thing for milling machines.

C Collets

C Collets are reduction sleeves for clamping smaller diameter cylindrical tool shanks. Used in Hi-Power Milling Chucks and MEGA Double Power Milling Chucks.

www.bigdaishowa.com

 

[extropic]

A couple look rough and shop made (aluminum?). The 23/32 is a rare bird.

 

[ddickey]

Look like drill bushings.