Standardization of Particle-Size Ranges

This report summarizes the activities of an inter society committee. The role of ASCE is emphasized in the report, and the ASCE position paper, as presented to the Intersociety Committee, is included as an appendix to the report. The Intersociety Committee observed that the upper size limits, in mm, now in common use are as follows: clay, 0.002, 0.0039, and 0.005; silt, 0.05 (No. 270 Sieve), 0.0625 (No. 230 Sieve), and 0.074 (No. 200 Sieve); sand, 2.0 (No. 10 Sieve), and 4.76 (No. 4 Sieve). This Committee reached agreement on the following statement: The prospects of attaining agreement on the upper size limits of clay seems good and we recommend the 0.002 mm limit. The possibilities of attaining agreement on the upper size limit of silt are slight to moderate, 0.0625 mm and 0.074 mm seem reasonable alternatives, with slight preference for the 0.074 limit. The prospect of attaining agreement on the upper sand size limit seems moderate to good and we recommend the 2.0 mm limit.