6 1/4" Half Round Needle File Cut 4 Grobet Swiss Precision is a file that is half round in shape, tapers in width and thickness. Total length of the file (including the handle) is 6 1/4" (160mm), the actual cutting portion of the file is approximately 3" (76 mm). Width of the file is 0.200" (5.10 mm) with a thickness of .073" (1.85 mm). Cut 4.