Diamond Pellets For Optical Glass

A diamond pellet is a small bonded block mounted in a ring on a grinding plate, and a plate carries dozens of them. The lens does not see one pellet — it sees the whole ring, and it sees them all at the same height. That is why pellet work is judged on consistency across a batch rather than on the performance of any single block.

We supply grit from 180# to 2000# for metal bond pellets and 800# to 3000# for resin bond pellets.

Why batch consistency matters more than peak performance

If one pellet in a ring of forty wears faster than its neighbours, that pellet stops touching the glass and the load transfers to the rest. The plate still cuts, so nothing looks wrong, but the surface develops a low zone that the polishing step cannot level out without removing far more material than planned. The defect is not a bad pellet; it is a batch where one pellet was harder than the others.

Metal bond for generating, resin for fine grinding

Metal bond pellets take the curve out of a generated lens and are run coarse, in the 180# to 400# range, where the job is stock removal and the glass is forgiving. Resin bond pellets follow at 800# to 3000#, and there the requirement flips: the bond has to release worn grit before it glazes, or the pellet polishes instead of grinding and the surface stops developing.

What we hold on the batch

Crystal strength is specified tight, because it is what keeps wear rate uniform from pellet to pellet. Particle size distribution is controlled on both ends, and magnetic content is reported per lot so that iron does not reach a surface that will later be coated.

Where It Goes Wrong

• Low zone on the lens surface. Uneven pellet wear across the ring, not a plate flatness fault.
• Pellet glazes instead of cutting. Bond too hard for the grit, or grit too fine for the pressure.
• Scratches that survive polishing. An oversize tail in the coarse pellet grade.
• Pellet life varies within one batch. Crystal strength spread too wide.