Hi all

I have been given a collet chuck for my lathe which has a different
type of collect to most I have found. The collets are similar to a 5c
collets except they have a thread of 12TPI at the base, are 1.25in dia
over the thread. They are 3.43 in long and have a fromt diameter of
1.5in.

Could someone help with an identification of the type and, if anyone
has any they want to sell, could you let me know. I am after 1/16 to 1
1/2 collets as time and pocket permit!!

Many thanks

On Wed, 24 Sep 2008 12:19:14 -0700 (PDT), Adrian G
 wrote:

>Hi all
>
>I have been given a collet chuck for my lathe which has a different
>type of collect to most I have found. The collets are similar to a 5c
>collets except they have a thread of 12TPI at the base, are 1.25in dia
>over the thread. They are 3.43 in long and have a fromt diameter of
>1.5in.
>
>Could someone help with an identification of the type and, if anyone
>has any they want to sell, could you let me know. I am after 1/16 to 1
>1/2 collets as time and pocket permit!!
>
>Many thanks

They are Crawford "Trugrip" collets. Quite rare and there are more
chucks than collets out there. Don't even ask the new price unless
you're backed by a sovreign wealth fund.

If you take the chuck apart you can see how it's made. There's a
stepped ring inside that can be easily remade to accept 5C threads and
then you can use proper 5c collets. The only downside is the fine
thread of 5C requires more turns of the chuck key and turning the
handle the wrong way, 5C are RH threaded and Trugrip are LH.

Charles

On 24 Sep, 20:28, Charles P  wrote:
> On Wed, 24 Sep 2008 12:19:14 -0700 (PDT), Adrian G
>
>  wrote:
> >Hi all
>
> >I have been given a collet chuck for my lathe which has a different
> >type of collect to most I have found. The collets are similar to a 5c
> >collets except they have a thread of 12TPI at the base, are 1.25in dia
> >over the thread. They are 3.43 in long and have a fromt diameter of
> >1.5in.
>
> >Could someone help with an identification of the type and, if anyone
> >has any they want to sell, could you let me know. I am after 1/16 to 1
> >1/2 collets as time and pocket permit!!
>
> >Many thanks
>
> They are Crawford "Trugrip" collets. Quite rare and there are more
> chucks than collets out there. Don't even ask the new price unless
> you're backed by a sovreign wealth fund.
>
> If you take the chuck apart you can see how it's made. There's a
> stepped ring inside that can be easily remade to accept 5C threads and
> then you can use proper 5c collets. The only downside is the fine
> thread of 5C requires more turns of the chuck key and turning the
> handle the wrong way, 5C are RH threaded and Trugrip are LH.
>
> Charles

Many thanks for that Charles. looks like another job for the weekend!!

Adrian