Table 2 

 Conversion Chart of Sediment Grain-Size Classifications 





UNIFIED SOILS 

 CLASSIFICATION 



ASTM 

 MESH 



MM 

 SIZE 



PHI 

 SIZE 



WENTWORTH 

 CLASSIFICATION 









4006.00 



1024 .00 



256 .00 



-12.0 

 -10.0 



BOULDER 



















COBBLE 





128.00 



107 .64 



90.51 



76 .00 



64.00 



-7 .0 

 -6.75 

 -6.5 

 -6 . 25 



COBBLE 



G 













R 















58.82 



-5.75 









COARSE 

 GRAVEL 





45.26 

 38.00 

 32.00 

 26. SI 

 22.63 

 19.00 

 16.00 



-5.5 



-5.25 



-5.0 



-4.75 



-4 .5 



-4.25 



-4.0 



PEBBLE 



A 









V 









13.45 



-3.75 









FINE GRAVEL 





11.31 

 9.51 



-3.5 

 -3.25 











2.5 



8.00 



-3.0 





E 







3 



6 .73 



-2.75 











3.S 



5.66 



-2.5 











4 



4.76 



-2.25 



















5 



4.00 



-2.0 





L 











Coarse 



6 

 7 



3.36 

 2.85 



-1 .75 

 -1.5 



GRANULE 







S 





8 

 10 

 12 



2 .35 

 2.00 

 1.68 



- 1 .25 



-1.0 



-0.75 











Very 











14 



1.41 



-0.5 



Coarse 











16 



1. 19 



-0.25 









A 



Medium 



18 



1 .00 



0.0 





S 













20 



0.84 



0.25 













25 



0.71 



0.5 



Coarse 











30 



0.59 



0.75 









N 





35 



0.50 



1 .0 





A 













40 



0.42 



1 .25 

















45 



0.35 



1 .5 



Medium 











50 



0.30 



1 .75 









D 





60 

 70 



0.25 

 0.210 



2.0 

 2.25 



















Fine 



80 

 100 



. 177 

 0. 149 



2.5 

 2 .75 



Fine 











120 



0. 125 



3 .0 





D 













140 



0. 105 



3.25 



Very 











170 



0.088 



3.5 



Fine 











200 



.074 



3.75 















230 

 270 



0.0625 

 0.053 



4.0 

 4 .25 



















325 



0.044 



4.5 









SILT 



400 



0.037 



.031 

 .0156 

 .0078 

 0.0039 



4 .75 

 5.0 

 6.0 

 7.0 

 8 .0 



SILT 



M 



















.0020 



9 . 





U 





CLAY 





. 00098 

 . 00049 

 .00024 



10.0 

 11.0 

 12.0 



CLAY 

















. 00012 



13.0 



COLLOID 



D 









. 00006 



14.0 







20 



