Hi all,

If you're thinking of using machine carbide inserts as a flat surface for
your ball pivot Lehman or S-G ball horizontal design, its probably
going to be (so-so) ~difficult to find UNCOATED inserts and; flat inserts
without the predominate center holes that the majority of shapes usually
have.
Almost all newer manufactured inserts have various coatings thereon....one
is kind of forced to hunt for older "surplus" uncoated inserts.

The prices of new inserts usually is > $10.00 up, each.  Older (> 20 years)
uncoated inserts can be ~ > $2-3 or so each.

Early (~ > 1970's era ) uncoated type carbide inserts aren't listed in the
newer offerings amongst the current web suppliers it seems.  Even finding
a old "speculation" insert like on E-Bay can be frought with the problem
that they don't often say if they are coated with whatever, or, are
uncoated.  Coatings can be a wide variety of material like tin, etc.
Photographs usually don't give a straight picture of whether they
are coated or not; a "shiny" reflective insert could still be coated with
something.  If the insert isn't pictured black; its probably coated.  Most
E-Bay
sellers of course don't know or care.  Of course, one could diamond
grind/lap off the coating.....

On E-Bay one seller that "often" does list whether they are coated or not;
and thats "hemlytool".  Be aware that "new" can also be
interpreted as old dated unused (surplus) stock.  Often the quanity they
sell is a turn-off; especially if you only need one or two. hemlytool has
alot
of inserts up for auction and afew that are uncoated and without centered
holes.  Most are square but they can be triangular, or diamond shaped also.

The surface of the insert may also need diamond lapping.  You may also have
to use the unmarked side as the marked side could be
etched or laser or whatever marked; which could interfere with the ball
contact.

The brand name "Valenite" seems to pop up quite often with older dated
uncoated inserts on E-Bay.

Take care, Meredith Lamb
Hi all,
 
If you're thinking of using machine carbide inserts as a flat surface for your ball pivot Lehman or S-G ball horizontal design, its probably
going to be (so-so) ~difficult to find UNCOATED inserts and; flat inserts without the predominate center holes that the majority of shapes usually have.
Almost all newer manufactured inserts have various coatings thereon....one is kind of forced to hunt for older "surplus" uncoated inserts.
 
The prices of new inserts usually is > $10.00 up, each.  Older (> 20 years) uncoated inserts can be ~ > $2-3 or so each. 
 
Early (~ > 1970's era ) uncoated type carbide inserts aren't listed in the newer offerings amongst the current web suppliers it seems.  Even finding
a old "speculation" insert like on E-Bay can be frought with the problem that they don't often say if they are coated with whatever, or, are
uncoated.  Coatings can be a wide variety of material like tin, etc.  Photographs usually don't give a straight picture of whether they
are coated or not; a "shiny" reflective insert could still be coated with something.  If the insert isn't pictured black; its probably coated.  Most E-Bay
sellers of course don't know or care.  Of course, one could diamond grind/lap off the coating.....
 
On E-Bay one seller that "often" does list whether they are coated or not; and thats "hemlytool".  Be aware that "new" can also be
interpreted as old dated unused (surplus) stock.  Often the quanity they sell is a turn-off; especially if you only need one or two. hemlytool has alot
of inserts up for auction and afew that are uncoated and without centered holes.  Most are square but they can be triangular, or diamond shaped also.
 
The surface of the insert may also need diamond lapping.  You may also have to use the unmarked side as the marked side could be
etched or laser or whatever marked; which could interfere with the ball contact.
 
The brand name "Valenite" seems to pop up quite often with older dated uncoated inserts on E-Bay.
 
Take care, Meredith Lamb