Grobet USA Checkering File Pillar 6 Inch Cut 00 25 lines per inch Parallel in width and gently tapered in thickness. Overcut is parallel to file edges and upcut is 90 degree to overcut. Useful for putting serrations on knife edges and to obtain a checkered design similar to a gun hand grip. Double cut top and bottom. Both edges are safe. 25 lines per inch. 1/2" wide x 5/32" thick. The most advanced CNC equipment and the best available robotic technology ensures that Grobet files are manufactured to the highest standards of dimensional accuracy, cutting performance, and service life. All Grobet products adhere to strict Quality Control procedures at each level of manufacturing. Every finished tool is individually tested to ensure superior quality. “Swiss Pattern” files means a type of fine file used for precision filing of jewelry, instrument parts, and dies. It does not necessarily mean that all “Swiss Pattern” files are Swiss made. Used by Professionals