Sieving in its most elemental definition is the separation of fine material from coarse material by means of a meshed or perforated surface. The technique was used as far back as the early Egyptian days as a way to size grains. These early sieves were made of woven reeds and grasses. Today the sieve test is the technique used most often for analyzing particle-size distribution.

Although at first look the sieving process appears to be elementary, in practice, there is a science and art involved in producing reliable and consistent results. In order to better understand sieving, there are several areas of sieve specifications that should to be explained, including:

1. What Are Test Sieves?

Test sieves are measuring devices used to determine the size and size distribution of particles in a material sample using wire mesh of different openings to separate particles of different sizes.

Test sieves usually consist of wire mesh held in a frame. In most laboratory applications the frame is round and is made from stainless steel or brass. The standard frame sizes are three, six, eight, ten, or twelve inch diameters and metric equivalents. The woven mesh can be made of stainless steel, brass, or bronze. For most applications stainless steel is the most common material used.

2. What Are the Limitations of the Test Sieve Procedure?

The main limitation with the construction of test sieves is the inherent nature of a woven product including control of sag when mounted and the uniformity of construction of the holding frame. It is also essential to maintain consistent sizing across all the openings in a piece of mesh.

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