When is an arbor a Collet?

[Glenn Brooks]

Hello all,

Several threads recently have discussed arbors and collets. For instance R-8 collets are called R-8 arbors and vice versa. What exactly is the difference??

Glenn

[duckman903]

I have R8 collets and an R8 arbor that I use for slitting saws so both terms are correct.

[Bill Shields]

technically, a COLLET squeezes...

an Arbor is something of a specific diameter on which you mount....something...usually a tool, but sometimes a part to machine.

so Arbor is INNIE - collet is OUTIE.....????

[SteveHGraham]

Think of a collet as a chuck and an arbor as a drill bit.

[CaptonZap]

From an on line dictionary;

ar·bor 2 (är′bər)
n.
1. An axis or shaft supporting a rotating part on a lathe.
2. A bar for supporting cutting tools.
3. A spindle of a wheel, as in watches and clocks.
4. pl. ar·bo·res (är′bə-rēz′) A tree, as opposed to a shrub.

[ctwo]

technically, a COLLET squeezes...

an Arbor is something of a specific diameter on which you mount....something...usually a tool, but sometimes a part to machine.

so Arbor is INNIE - collet is OUTIE.....????

or the other way round? Outie seems like an arbor.

[John Evans]

..
an Arbor is something of a specific diameter on which you mount....something...usually a tool, but sometimes a part to machine.

Unless it is an EXPANDING arbor ! Of which I have quite a collection.

[earlgo]

In my befuddled mind, a collet has slots, or in the case of the Jacobs stuff, rubber flexures between metal parts, and is expandable or contractable by the action of a drawbar or such.
An arbor is something on which a part or tool is mounted. It is usually solid. (The exception, of course, is the expandable arbors on which a tool or part is mounted.)
But I am over 3 score and 10 so am easily befuddled.

--earlgo

[Glenn Brooks]

All, or most, of the tool manufactures on line sell R 8 collets as both collets and arbors. Hardinge actually lists a collet arbor whatever that is...

Personally I think of an arbor as some round holder that grippes the ID of the work, e.g. Goes into a center hole of some kind, and a Collet is something that grips around the outside diameter of the work.

[spro]

An expanding collet becomes an arbor in use but it is an exception.

[seal killer]

All--

I like the Bill's answer: a collet squeezes. That's easy to remember. And, the exception is the exception.

--Bill