Grind blocks made of high quality, corrosion resistant stainless steel for extended use; Dual channel designs; Groove depth is graduated on the block showing microns and Hegman scales; Read more. Technical Attributes. Technical Specifications. Path Size 1.3 x 13 cm; Scales µm, Hegman; No. of Paths 2; Range 0 - 25 µm; Range 8 - 6 Hegman; General.