Ensoll endless diamond wire loops (ring diamond wire) are supplied with full-plated, segmented and threaded coatings in 0.25-2.5 mm diameters, matched to your material and cut width. Loops are made in-house with documented joint strength, so kerf and wire life stay consistent batch to batch. Diameters, coatings and lengths are made to order for optical glass, sapphire, graphite, magnetic materials and silicon.

https://www.ensolltools.com/product/diamond-wire-loop-endless-diamond-cutting-wire/