4" Diamond Blades

["Charles Kibby" <ckibby@zzzzzzzzzzz>]

'Stop being so cheap' is a good starting point, but not always the most
relevant when it comes to diamond technology these days. Thirty years ago
diamonds were a rare and expensive tooling device, but these days every
technological wannabe has an offering.  Just remember this: Except for rare
and unavailable materials, industrial diamonds are essentially all the same.
There are two main issues to consider: 1) the total amount of diamond
particles in the matrix, 2)the resistance to abrasion of the matrix material
itself.

Assume a status quo of relative equilibirium regarding the overall quality
of blades from different sources; the main thing to remember is that as a
diamond particle abrades its merry way through a softer material, (and by
definition and the standards of the MOH scale, all other materials are
softer than diamonds), it is rounding the edges of its cutting surfaces.
The purpose of a good diamond cutting tool is present sharp diamond cutting
edges as regularly as possible.  E.G.: A granite blade will have a softer
matrix in order to wear out the matrix more rapidly and present newer,
sharper cutting edges to the relatively hard material. Conversely, a marble
or limestone blade will have a harder matrix, because newer, sharper diamond
particles and edges do not have to be exposed as often or as rapidly.  This
is essentially true for all diamond tooling, whether cutting blades or
shaping bits, or whatever.

To return to your question, the best and most durable blades are by no means
necessarily the most expensive.  Trial and error is the best way,
unfortunately.  I have been doing masonry restoration for twenty years to
support my sculpture habit, and in all that time I cannot honestly say that
price determined the most appropriate blades for my (income-producing)work.
One manufacturer's offering might work very well in old board-formed
concrete and granite, but I would stay away from it if the job involved
limestone or some other calcareous material. Hopefully this will at least
help in making a more informed purchasing decision.

Good Luck,

Chaz