G.C.Hawley & Associates (Industrial Minerals Consulting)

Particle Size Conversions

Sieve US Mesh	Sieve Tyler	Sieve British standard	Opening (microns)	Opening (inches)
	2.5		7920	0.312
2.5			8000	0.315
3			6730	0.265
	3.0		6680	0.263
3.5			5660	0.223
	3.5		5610	0.221
4			4750	0.187
	4		4700	0.185
5			4000	0.157
	5		3960	0.156
6		5	3350	0.132
	6		3360	0.131
7		6	2830	0.111
	7		2790	0.110
8	8	7	2380	0.094
10	9	8	2000	0.079
12		10	1680	0.066
	10		1650	0.065
14	12	12	1410	0.055
16		14	1190	0.047
	14		1170	0.046
18	16	16	1000	0.039
20	20	18	840	0.033
25	24	22	710	0.028
30	28	25	590	0.023
35	32	30	500	0.020
40	35	36	420	0.0165
45	42	44	350	0.0138
50	48	52	297	0.0117
60	60	60	250	0.0098
70	65	72	210	0.0083
80	80	85	177	0.0070
100	100	100	149	0.0059
120	115	120	125	0.0049
140	150	150	105	0.0041
170	170	170	88	0.0036
200	200	200	74	0.0029
		240	66	0.026
230	250		62	0.0024
270	270		53	0.0021
325	325		44	0.0017
400			38	0.0015
550			25	0.0009
635			20	0.00079
1000			13	0.00050
1200			10.2	0.00039
2300			6	0.00025

Particle Diameter Microns	Particle Diameter Inches	Grind gauge Hegman NS	Grind gauge Production Club	Blaine number
102	0.0040	0	0
95.3	0.00375	0.5
91.4	0.0036		1
88.9	0.0035	1
82.6	0.00325	1.5
81.3	0.0032		2
76.2	0.003	2
71.1	0.0028		3
69.9	0.0275	2.5
63.5	0.0025	3
61	0.0024		4
57.2	0.00225	3.5
50.8	0.002	4	5
44.5	0.00175	4.5		3000
40.6	0.0016		6
38.1	0.0015	5		3300
31.8	0.00125	5.5
30.5	0.0012		7
25.4	0.0009	6		4000
20.3	0	0008		8
19.1	0.00075	6.5		4600
12.7	0.00050	7		5700
6.4	0.00025	7.5	9	8000
0	0	8	10

Blaine Formula P = 85% passing
P = [ 20303/Blaine number ] ² microns

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	Tel: 1-877-335-8923 Email: info@geohawleyminerals.com		Tel: 613-936-1962 Email: info@geohawleyminerals.com