Silica sand is often described by mesh, such as 20/40 or 30/60. Mesh numbers refer to standard test sieves, and each sieve number corresponds to a specific opening size. This chart converts common sieve numbers to micrometres (µm) and millimetres so you can compare specifications written in different units.
What a mesh number means
A mesh number identifies a standard test sieve. The higher the number, the smaller the opening, so 100 mesh is finer than 30 mesh. The openings below follow ASTM E11, the standard for test sieves that most mesh specifications refer to.
Indian standards usually name sieves by their aperture instead of a number. For example, the 600 µm IS sieve used in concrete sand grading has the same nominal opening as ASTM No. 30.
Mesh to micron and millimetre chart
Nominal openings of common ASTM E11 sieves used for sand:
- No. 10: 2.00 mm (2000 µm)
- No. 16: 1.18 mm (1180 µm)
- No. 20: 0.850 mm (850 µm)
- No. 30: 0.600 mm (600 µm)
- No. 40: 0.425 mm (425 µm)
- No. 50: 0.300 mm (300 µm)
- No. 60: 0.250 mm (250 µm)
- No. 70: 0.212 mm (212 µm)
- No. 100: 0.150 mm (150 µm)
- No. 140: 0.106 mm (106 µm)
- No. 200: 0.075 mm (75 µm)
Reading a range such as 30/60 mesh
A range written as 30/60 describes sand that passes through the No. 30 sieve and is retained on the No. 60 sieve. Using the chart, that is roughly 600 µm to 250 µm, or 0.60 mm to 0.25 mm.
In practice a small share of grains falls outside any range. A complete specification states how much is allowed on the coarser sieve and through the finer one, rather than giving the range alone.
Specifying grain size clearly
Whether you use mesh, micrometres or millimetres, name the sieve standard and give percentage limits for each relevant sieve. Ask the supplier for a sieve analysis report in the same units so you can check it directly against your requirement.
Foundry buyers often add an AFS grain fineness number, which is calculated from the full sieve analysis. Our foundry sand guide explains how to use AFS alongside the distribution.
Grain sizes on our product pages
Our product pages list indicative grain sizes in millimetres, for example 0.15 to 2.0 mm for construction sand and 0.2 to 1.0 mm for recreation sand. Use the chart to compare these with a mesh specification, then confirm the exact grading for your order with our team.
Explore the relevant grades
- Foundry Grade Silica Sand
- Silica Sand for Chemical Industries
- Construction Sand
- Silica Sand for Recreation Work
Request a silica sand quote with your specification, quantity and delivery location, or contact our team.