Part 631 National Engineering Handbook Engineering Classifiion of Earth Materials Chapter 3 3–iv (210–VI–NEH, Amend. 55, January 2012) Table 3–9 USCS components and modifiers 3–15 Table 3–10 Soil components and significant properties 3–16 Table 3–11 Gradation descriptors for coarsegrained soils 3–18 Table 3–12 Manual field test procedures for the .