01 — Sieve numbersSieve numbers (No. 3½ to No. 635)
| Sieve No. | Opening (mm) | Opening (µm) | Opening (in) | Typical wire (mm) | Tyler mesh |
|---|---|---|---|---|---|
| No. 3½ | 5.6 | 5,600 | 0.2205 | 1.6 | 3.5 |
| No. 4 | 4.75 | 4,750 | 0.187 | 1.6 | 4 |
| No. 5 | 4 | 4,000 | 0.1575 | 1.4 | 5 |
| No. 6 | 3.35 | 3,350 | 0.1319 | 1.25 | 6 |
| No. 7 | 2.8 | 2,800 | 0.1102 | 1.12 | 7 |
| No. 8 | 2.36 | 2,360 | 0.0929 | 1 | 8 |
| No. 10 | 2 | 2,000 | 0.0787 | 0.9 | 9 |
| No. 12 | 1.7 | 1,700 | 0.0669 | 0.8 | 10 |
| No. 14 | 1.4 | 1,400 | 0.0551 | 0.71 | 12 |
| No. 16 | 1.18 | 1,180 | 0.0465 | 0.63 | 14 |
| No. 18 | 1 | 1,000 | 0.0394 | 0.56 | 16 |
| No. 20 | 0.85 | 850 | 0.0335 | 0.5 | 20 |
| No. 25 | 0.71 | 710 | 0.028 | 0.45 | 24 |
| No. 30 | 0.6 | 600 | 0.0236 | 0.4 | 28 |
| No. 35 | 0.5 | 500 | 0.0197 | 0.315 | 32 |
| No. 40 | 0.425 | 425 | 0.0167 | 0.28 | 35 |
| No. 45 | 0.355 | 355 | 0.014 | 0.224 | 42 |
| No. 50 | 0.3 | 300 | 0.0118 | 0.2 | 48 |
| No. 60 | 0.25 | 250 | 0.0098 | 0.16 | 60 |
| No. 70 | 0.212 | 212 | 0.0083 | 0.14 | 65 |
| No. 80 | 0.18 | 180 | 0.0071 | 0.125 | 80 |
| No. 100 | 0.15 | 150 | 0.0059 | 0.1 | 100 |
| No. 120 | 0.125 | 125 | 0.0049 | 0.09 | 115 |
| No. 140 | 0.106 | 106 | 0.0042 | 0.071 | 150 |
| No. 170 | 0.09 | 90 | 0.0035 | 0.063 | 170 |
| No. 200 | 0.075 | 75 | 0.003 | 0.05 | 200 |
| No. 230 | 0.063 | 63 | 0.0025 | 0.045 | 250 |
| No. 270 | 0.053 | 53 | 0.0021 | 0.036 | 270 |
| No. 325 | 0.045 | 45 | 0.0018 | 0.032 | 325 |
| No. 400 | 0.038 | 38 | 0.0015 | 0.03 | 400 |
| No. 450 | 0.032 | 32 | 0.0013 | 0.028 | 450 |
| No. 500 | 0.025 | 25 | 0.001 | 0.025 | 500 |
| No. 635 | 0.02 | 20 | 0.0008 | 0.02 | 635 |
02 — Coarse sievesCoarse sieves (inch designations)
| Designation | Opening (mm) | Opening (in) | Typical wire (mm) |
|---|---|---|---|
| 1 in. | 25 | 0.984 | 3.55 |
| 7/8 in. | 22.4 | 0.882 | 3.55 |
| 3/4 in. | 19 | 0.748 | 3.15 |
| 5/8 in. | 16 | 0.63 | 3.15 |
| 1/2 in. | 12.5 | 0.492 | 2.5 |
| 7/16 in. | 11.2 | 0.441 | 2.5 |
| 3/8 in. | 9.5 | 0.374 | 2.24 |
| 5/16 in. | 8 | 0.315 | 2 |
| 1/4 in. | 6.3 | 0.248 | 1.8 |
Source: ASTM E11 nominal dimensions. Always refer to the current standard for tolerances.
03 — In practiceCommon sieves in soil and aggregate testing
- No. 4 (4.75 mm) — boundary between gravel and sand.
- No. 10 (2.00 mm) — boundary between coarse and medium sand (USCS); gravel and sand in AASHTO.
- No. 40 (425 µm) — boundary between medium and fine sand (USCS); used to prepare Atterberg limits samples.
- No. 200 (75 µm) — boundary between sand and fines (silt and clay).
04 — FAQFrequently asked questions
What is the size of a No. 4 sieve?
A No. 4 sieve has a 4.75 mm (0.187 in) opening. In soil and aggregate testing it is the dividing line between gravel and sand.
What is the size of a No. 200 sieve?
A No. 200 sieve has a 75 µm (0.075 mm, 0.0029 in) opening. Material passing the No. 200 sieve is classified as fines (silt and clay).
What is the difference between sieve number and mesh?
For US standard sieves, the sieve number is approximately the number of openings per inch (mesh), but the sieve is officially defined by its opening size in mm or µm, not by the count.
What does ASTM E11 cover?
ASTM E11 is the US specification for woven wire test sieve cloth and test sieves. It sets nominal openings, permissible variations and typical wire diameters from 125 mm down to 20 µm.