I think you are confusing sintered with plated. Not the same thing
at all. Sintered is a much better quality and longer lasting
product. Not cheap, but usually worth it.
I have used plated and sintered diamond products for almost 35 years.
As a faceter, a well-manufactured, top of the line plated disc will
last a few months, costs maybe $120. A sintered disc will last many,
many years, but costs almost $400. Obviously, the sintered is cheaper
in the long run, but, in my experience, most jewelers and bench
people are "cheap".....so they hurt themselves. And, many workers use
the small tools with no lubricant or with water. They need to be used
with a proper oil to maintain life, but, of course, many
manufacturers will say water is fine. That's nonsense and
self-serving. A good water-soluble oil is proper with ALL diamond