Fowler 1-2-3 Block Set Features include... 23 holes for easy clamping 5 Tapped, 18 Untapped Sold in Matched Pairs Dimensional Accuracy: 0.0001" Very useful in mounting work for precision grinding, layout work, etc. Blocks hardened to 55-60 Rockwell C. Ground to surface finish 6-16 micro inches Includes 5 Mounting Blots (3/8" - 16)
