Diamond Impregnated Tools

Jewelry Discussion
1

I have what may seem to many a very dumb question. I have just become
the owner of an 8 inch flat lap,and until recently didn’t even think
about this even though I have owned 8 inch diamond lapidary wheels
for years.What are the different ways that diamonds are impregnated
into flat laps for example and which is the better of the choices.
When I purchased the flat lap, I received several peel-off diamond
discs which are stuck to plates. Needless to say,I’m not satisfied
with these. What I want are discs that the diamonds are impregnated
into the disc itself.Perhaps metal,perhaps not,whatever is best.I’ve
seen the term sintered(sp?) but don’t understand its meaning,or what
other choices there are. Thanks in advance,

John Barton

2

John,

Funny you should ask this question. Last night at our diamond class
here in Tampa we visited a lab on campus that is working on making
these type of applications. They are synthesizing diamonds in wafers.
We asked a similar question. From the technique that they use, it
seems there is a problem with adhering to the host surface. I would
think that in the future the techniques will be perfected to
accommodate this. It was amazing the potential for all the
applications in synthesizing. Our host told us the technique has been
around for over 20 years, most labs now at different universities are
working on application use.

Eva

3

John,

Before I get started, please let us know what you want to use the
laps for. There is at least one professional faceter (Wayne Emery)
and one amateur (me) on the list regularly. There are probably others
who don’t talk so much.

There are several basic types of lap. I’m guessing that you bought
what is called a “master lap”, which isn’t intended to cut or polish
by itself, but only to provide a smooth flat surface to hold other
materials, such as the peel-off diamond you mentioned.

One very popular kind for cutting and even pre-polish is the metal
bonded lap. Diamond is bonded to the surface by a metal coating.
These work well in grits from 100 - 1200, and last quite a long time.
Crystallite Solid Steel laps are a popular choice.

There are also laps that are bonded by other materials, like the
Nubond (which may be an epoxy, I don’t know for sure.) These tend to
produce a finer finish for a given grit. A 1200 grit Nubond will
produce a very good prepolish on quartz or beryl, for example.

Sintered laps are the ultimate in cutting laps. The diamond is
actually mixed into a deep layer of metal. They are expensive, but
last a very long time, produce a good finish, yet cut quite
aggressively.

Then, there is a large class of laps which are used with loose
cutting or polishing compounds. If diamond is used, it’s spread on
the surface and pressed in, usually with a tool of some kind. The
cutting or polishing compound needs to be renewed periodically, but a
few carats of diamond powder will last a long time, and it’s
inexpensive.

Laps in this category can be made of various materials - copper,
tin, phenolic, alloys. One which has acquired a large following and
is very versatile is the BATT lap, www.battlap.com. I use it for both
cutting, with large grits (325 mesh is good) and polishing grits
(50K, 100K).

It’s a big subject. Let us know what your intended use is, and we
can probably be more specific and point you to more

Al Balmer
Sun City, AZ

4

Hi, John. There’s lots of options for diamond tools and laps. Your
main question though is easy. There’s two kinds of diamond
impregnated tools: sintered and plated. Sintering is the same
process that is used to make carbide tools and inserts. A tool and
die presses a shape out of a mix of metals or whatever, then that
shape gets baked in an oven, which makes it hard. In the case of
diamond it’s a mix of a metal or solder that I don’t know what is,
and diamond grit. This means that the entire working part of the tool
is filled with diamond, and exposes fresh grit as it wears, just like
a grinding wheel. Plated tools have diamond grit sprinkled on the
surface, and then a heavy plating of usually nickel is applied,
which coats it all and holds the diamond. Obviously sintered tools
are far superior, and obviously they are also far more expensive.
There’s other ways, too, all of which involve charging the wheel,
like a polishing wheel - using diamond powder and oil, which is what
diamond cutters traditionally use, diamond paste, which I like, and
for polish there’s even diamond sprays. It’s not really that
complicated - whatever wheels you use will either already be charged,
or will require charging, in which case use the compound that suits
the wheel. No doubt you’ll also get replies from other lapidaries,
too…

http://www.donivanandmaggiora.com

5

John Barton-

A traditional way of making diamond laps for cutting colored stone is
to charge diamond bort (say 260, 600, 0r 1200 grit) into a copper or
bronze lap. This still works well- if one can obtain the metal for
the lap. Another way of attaching diamond grit to a tool is through a
layer of nickel plating on a steel lap, and these are available
commercially (Crystalite laps are an example). Yet another way is by
using a plastic binder contianing diamond grit throughout, either on
a fairly thick aluminum backing plate (Raytech), or on so-called
"circuit boards" which require a master lap to hold them in position.
Plated steel laps are said to be the truest running. Zinc, tin and
BATT laps have traditionally been used for pre-polish and polish on
hard stones. Some cutters have also charged BATT laps wih coarser
grits and used them as cutting laps.

Sintered tools are made with the cutting area made of loose
particles of metal with the diamond particles mixed in. When the
mixture is held in place and brought to a high temperature so that
the metal particles fuse together, the result is a sintered diamond
saw or drill. They cost more than plated tools, but last longer since
the diamond grit is not just on the surface. Saw rims may be
continuously sintered, or may be segmented.

There are variations on the steel lap idea: pebbly surfaces or
circular raised diamond charged areas surrounded by channels or low
areas intended to carry away cutting debris (swarf) and provide a
flow of cooling fluid to the cutting area.

If you check out web sites for diamond tools you will find more

I hope this helps.
Richard Davies

6

there are no dumb questions on Orchid…its about learning…

Sintered diamond tools are the creme of the crop…the diamond is
bound to the metal by heating the metal to the point of --uh,
sintering…at which time the diamonds are partially embedded into
the metal due to the high temperature and when worn down a bit from
use a new surface of diamond is exposed and available to cut - these
last longest

Electroplated diamond is what is available at most home stores.the
diamond is surface bound to the metal in a variety of ways, but when
it pops off it is gone…these are the mid priced and cheaper
products they last perhaps, half s long as sintered laps,burs,
cut-off wheels etc.

diamond coated products are what one finds at flea markets, harbor
freight tools, and box lots from Chinese sources.this is the
leftover industrial diamond usually applied with an epoxy based
coating or lesser. the diamod is very uneven, the grits are usually
mixed, and you could make your own with more efficacy than those
tools can gie.next time you are at a flea market for instance look at
the wet/dry diamond saw blades- you can see with the naked eye the
sparse coating of particles on the surfaces…recently there ws an
Orchid thread ( or SNAGNET??) about making ones own laps and cutting
wheels with diamond spray and used wet/dry tile cutting blades…Opal
cutters are fond of making their own, and anyone can make useable
excellent performers with this method of applying diamond spray in
various grits to various substrates to get a desired result- they are
inexpensive,great to keep in mind for an electrical stormy day when
one really shouldn’t be using power anyway!

i hope this gives you a very basic idea of the differences in
industrial diamond application methods.

7 
to make your own lap, if you start with a copper disk, or as
others have suggested the batt lap, you can impregnate the surface
with diamond by dry sprinkling diamond dust on the surface, and
then using a roller to force the powder into the surface.

diamond powder is cheap! $1 or so a carat, sized and graded. lasco,
crystallite, diamond pacific, others

regards
Mark Zirinsky
denver

8

I have no quarrel with what you say, but would like to add to it.

Sintered tools cut differently than plated. Sometimes plated is
better. I use sintered saw blades as well as plated saw blades. If
I’m cutting expensive crystal opal rough I use a very thin plated
blade. If I were cutting matrix opal I would use a sintered blade.

KPK

9

Thanks to all for the invaluable info regarding diamond impregnated
tools. It was exactly what I was looking for, and helps
tremendously. I am one of those that doesn’t like to pay twice for
the same thing, i. e., buying cheap the first time only to have to
turn around and buy the better choice later. Some asked what I would
be using these laps on so they could give a clearer answer perhaps.
I will be using them on everything from turquoise to dino bone,
lapis, sugilite, pietersite, jet, spiny oyster, and jade. I do only
cabs, no faceting. Again thanks to all who responded and any more
help and advice is appreciated.

Best wishes, John Barton

10

Hi John, we made contact last winter about the “flat lap”. I use it
all the time. The diamond laps come in 80, 160, etc…are all solid

  • mounted on the round base. Some of the finer diamond papers, which
    have the sticky backing, are for refining the first “grinding”
    “shaping” of a rock or whatever fossil (dinosaur bone) you are
    attempting to polish. I use mine for channel inlay, cabbing, shaping,
    polishing.

I order mine from Ameritool…look on their web and you will find
all the laps you would need. Just a satisfied customer.

Hope this helps you and others.
RMChristison

11 
I will be using them on everything from turquoise to dino bone,
lapis, sugilite, pietersite, jet, spiny oyster, and jade. I do only
cabs, no faceting

John, It appears this thread was a bit of overkill because the
purpose of your question was not clear. Now that we know your
purpose, I suggest you go to www.gravescompany.com which will provide
an online catalog (or online info) that will answer all your
questions. Check out the books section for books by Cox, Drake,
Downing and others on cabbing. It will save you a lot of time.

Notice: I work at Graves now and then.

Cheers from Don at The Charles Belle Studio in SOFL where simple
elegance IS fine jewelry!