3M™ 668X Diamond Lapping Film Disc 3M™ The 3M™ 668X diamond lapping film disc is a high-precision abrasive designed for polishing and finishing hard surfaces such as ceramics, optical glass, metals, and composites. This disc features a durable polyester film backing coated with diamond particles, providing fast cutting action and a smooth, consistent finish. With 3M's diamond technology, the 668X disc ensures consistent and long-lasting performance, even in the most demanding applications, while minimizing the risk of scratches and defects on the worked surface. This disc is particularly well-suited for use in electronics, optics, and industrial manufacturing, where precision and finish quality are critical. Learn more