Soil sieve sizes

Wednesday June-18 2025  15:02:54

Soil sieve size is a key parameter in soil particle analysis and is used to classify soil texture or engineering purposes. There are multiple standards for the hole size of soil sieves, and which one to choose depends on the size of the soil particles you want to analyze. When conducting soil particle analysis, the appropriate sieve size should be selected according to actual needs to ensure that soil particles of different particle sizes can be effectively separated.

Common sieve sizes for geotechnical tests

Coarse sieve (round hole): hole diameters are 100mm, 80mm, 60mm, 40mm, 20mm, 10mm, 5mm, 2mm.

Fine sieve (square hole): equivalent hole diameters are 2.0mm, 1.0mm, 0.5mm, 0.25mm, 0.10mm, 0.075mm.

Common apertures of standard soil sieves: 0.074mm, 0.25mm, 0.5mm, 1mm, 2mm, 2.5mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 12mm, 13mm, 20mm, 40mm, 60mm.

Standard soil sieve mesh number corresponding aperture

Sieve hole size (mm)	standard mesh number	sieve size (mm)	standard mesh number
4.75	4 mesh	1.70	12 mesh
4.00	5 mesh	1.40	14 mesh
3.35	6 mesh	1.18	16 mesh
2.80	7 mesh	1.00	18 mesh
2.36	8 mesh	0.850	20 mesh
2. 00	10 mesh	0.710	25 mesh
0.600	30 mesh	0.212	70 mesh
0.500	35 mesh	0.180	80 mesh
0.425	40 mesh	0.150	100 mesh
0.355	45 mesh	0.125	120 mesh
0.300	50 mesh	0.106	140 mesh
0.250	60 mesh	0.090	170 mesh
0.250	60 mesh	0.0750	200 mesh

Common soil sieve sizes

Coarse-grained soil (sand, gravel): 63mm, 31.5mm, 16mm, 8mm, 4.75mm (commonly used to distinguish gravel and sand), 2mm (the boundary between sand and gravel), 1mm, 0.5mm, 0.25mm, 0.125mm, 0.075mm (the boundary between sand and silt)

Fine-grained soil (silt, clay): 0.063mm (the boundary between silt and clay, the commonly used sieve number is 200 mesh), 0.038mm, 0.02mm, 0.002mm (the upper limit of clay particles)

In soil analysis, sieving is a common method used to determine the size distribution of soil particles. According to different standards and analysis purposes, a series of sieves with different apertures will be used.

①2 mm sieve hole: This is the most commonly used sieve size in soil sample pretreatment. Soil samples that pass through the 2 mm sieve hole are usually called fine soil and are used for subsequent physical and chemical analysis, such as particle size analysis, organic matter content determination, etc. Particles larger than 2 mm are usually considered gravel or coarse aggregate and are weighed or removed separately in some analyses.

②0.063 mm sieve hole: This is a very important dividing point in soil particle size analysis. Particles larger than 0.063 mm are usually measured by sieving (such as sand). Particles smaller than 0.063 mm (such as silt and clay) are usually measured by Stokes' law to determine their settling velocity due to their small particle size, thereby inferring the particle size.

Soil sieve size list

Sieve size (mm)	Corresponding mesh number (approximately)	Purpose description
2.00mm	10 mesh	Separation of gravel and coarse sand
1.00mm	18 mesh	Coarse sand screening
0.50mm	35 mesh	Medium sand screening
0.25mm	60 mesh	Fine sand screening
0.075mm	200 mesh	Dividing line: the boundary between sand and silt (fine-grained soil)
0.063mm	230 mesh	Silt screening, often used for analysis of finer particles

Standard sieve sizes commonly used in soil particle analysis and corresponding mesh numbers

Soil sieve size refers to the aperture size of the standard sieve used for soil particle analysis, usually expressed in millimeters or microns. Mesh number is also often used to indicate the coarseness of the sieve, which means the number of holes per inch of length. The larger the mesh number, the smaller the sieve hole.

Sieve size (mm)	Sieve size (μm)	Approximate mesh size (Mesh)	Main purpose/corresponding particle level	Sieve size (mm)	Sieve size (μm)	Approximate mesh size (Mesh)	Main purpose/corresponding particle level
75.0	75000	3	Granite, large pebbles	63.0	63000	3.5	Pebble
50.0	50000	4	Pebble	37.5	37500	5	Used upper limit of coarse gravel and engineering filling materials
31.5	31500	6	Gravel	26.5	26500	7	Gravel
19.0	1900 0	8	gravel	16.0	16000	10	gravel
13.2	13200	12	gravel	9.50	9500	16	gravel/coarse sand
6.70	6700	20	coarse sand	4.75	4750	4	sand upper limit (key sieve), distinguishing gravel from sand
2.36	2360	8	sand	2.00	2000	10	sand
1.18	1180	16	sand	1.00	1000	18	sand
0.850	850	20	sand	0.710	710	25	sand
0.600	600	30	sand	0.500	500	35	sand
0.425	425	40	sand	0.355	355	45	sand
0.300	300	50	sand	0.250	250	60	sand
0.212	212	70	fine sand	0.180	180	80	fine sand
0.150	150	100	fine sand/powder	0.125	125	120	fine sand/powder
0.106	106	140	powder	0.090	90	170	powder
0.075	75	200	upper limit of powder/lower limit of clay (key sieve), distinguish sand/powder from clay	0.0 63	63	230	silt/clay
0.053	53	270	silt/clay	0.045	45	325	clay
0.038	38	400	clay	0.032	32	450	clay
0.025	25	500	clay	0.020	20	635	clay
0.015	15	800	clay	0.010	10	1250	clay
0.005	5	2500	colloid	0.002	2	6350	colloid

Core sieve hole:

4.75mm (No.4 sieve): This is the key boundary to distinguish gravel from sand. Particles larger than this size are gravel, and particles smaller than this size enter the analysis scope of sand, silt, and clay.

0.075mm (No.200 sieve): This is the key boundary for distinguishing sand/silt from clay. Particles smaller than this size need to be further analyzed by sedimentation, because sieving is inefficient for such fine particles and easily clogs the sieve.

Soil texture classification: The relative percentage of sand, silt, and clay in the soil (usually based on particle size boundaries such as 2mm-0.05mm-0.002mm or 2mm-0.063mm-0.002mm) determines the texture of the soil (such as sand, loam, clay, etc.). The 0.075mm sieve in the table above is one of the important tools for obtaining these percentage data.

Soil sieve sizes are standardized and serialized, and core sieve holes (such as 4.75mm and 0.075mm) play a vital role in distinguishing soil particles of different particle size levels (gravel, sand, silt, clay). The particle gradation data obtained through sieving analysis is the basic information for understanding and describing soil physical properties, engineering design and agricultural management. The specific sieve size to be selected depends on the purpose of the analysis and the standard specifications to be followed.