Particle size comparison chart

There are a number of units and scales commonly used to measure particle size. These either refer to average particle diameter measured in units of length, typically microns, or refer to a smallest mesh size through which the particles will pass. The following table sets out conversions between a variety of systems:

 

US MESH	TYLER SCREEN	BSS MESH	MICRONS	INCHES	MILLIMETRES	EXAMPLE
18	16	16	1000	0.0394	1.000
20	20	18	841	0.0331	0.841
25	24	22	707	0.0280	0.707	beach sand
30	28	25	595	0.0232	0.595
35	32	30	500	0.0197	0.500
40	35	36	400	0.0165	0.400
45	48	44	354	0.0138	0.354
50	48	52	297	0.0117	0.297
60	60	60	250	0.0098	0.250	fine sand
70	65	72	210	0.0083	0.210
80	80	85	177	0.0070	0.177
100	100	100	149	0.0059	0.149
120	115	120	125	0.0049	0.125
140	150	-	105	0.0041	0.105
170	170	170	88	0.0035	0.088
200	200	200	74	0.0029	0.074	portland cement
230	250	240	63	0.0024	0.063
270	270	-	53	0.0021	0.053
325	325	350	44	0.0017	0.044
400	400	-	37	0.0015	0.037	plant pollen
550	-	-	25	0.0009	0.0025
800	-	-	15	0.0006	0.015
1200	-	-	12	0.0005	0.012
1250	-	-	10	0.0004	0.010
2500	-	-	10	0.0004	0.010	large bacteria
4800	-	-	2	0.0001	0.002	smoke particle