WIRE-CLOTH SIEVES FOR TESTING PURPOSES

 IV. STANDARD SPECIFICATION (ASTM E 1) FOR

WIRE-CLOTH SIEVES FOR TESTING PURPOSES

1. Scope:

This specification covers the design and construction of sieves wherein a screening medium of

Woven wire cloth is mounted in a frame for use for precision testing in the classification of materials.

Methods of checking and calibrating sieves are included as information in the appendix.

2. Wire Cloth Sieve Requirements:

2.1 The openings of the wire cloth of successive standard sieves progress from a base of 1 mm in the

ratio of approximately (2:1)^0.25.

2.2 Wire cloth for standard sieves shall be woven from stainless steel, brass, bronze, or other suitable

wire with a plain weave. The wire shall not be coated or plated.

2.3 Wire cloth shall conform to the dimensional requirements of Table 3.2 (see Note). The average

opening (distance between parallel wires measured at the centre of the opening), both in the warp

and shoot directions, measured separately, shall conform to the value in Column 1, within the

permissible variation in average opening size given in Column 4. The maximum individual opening

shall not exceed the value given in Column 6. Not more than 5% of the openings shall fall within the

range between the values given in Column 5 and Column 6.

The average diameter of the warp and shoot wires, taken separately, shall be within the permissible

range as specified by Column 7 and Footnote.

2.4 Both the warp and shoot wires shall be crimped in such a manner that they will be rigid when in

use.

2.5 All measurements of openings and wire diameters shall be made on the wire cloth mounted in

the completed sieve. Opening measurements shall be made along the mid points of the opening.

2.6 There shall be no punctures or obvious defects in the cloth.

NOTE: The dimensional tolerances given in Columns 4, 3, and 6 can be described with Figures and equations given

below. These equations apply separately in both warp and weft (shoot) directions, with all measurements being

made on the midpoints of the opening (Figure 3.4).

Standard Specification for Wire Cloth and Sieves for Testing Purposes,ASTM E11-01 Standard Specification for Wire Cloth and Sieves for Testing Purpose

3. Dimensions, Mass and Permissible Variations:

3.1 Column 4: In Column 4 values, the permissible variations of the average opening from the

standard sieve designation shall be stated as the Y value. The average opening size shall not exceed

+Y, where:

 

Y = w^0.98/27+1.6

NOTE: Here w is the width of sieve opening.

3.2 Column 6: In Column 6 values, the maximum individual opening shall be stated as w+X

where:

X=2*w^0.75/3+4*w^0.25

NOTE: The formulas for both X and Y apply only where X, Y and w are expressed in micrometres.

3.3 Column 5: In Column 5 values, the intermediate tolerance shall be stated as w+Z

where:

Z= X +Y

Not more than 5% of the openings shall have sizes between w+Z and w+X. When a sieve has less

than 50 openings, not more than 3 openings shall fall within the limits of w+Z and w+X.

4. Frames:

4.1 General Requirements: Frames for wire cloth sieves shall be made from non-corrosive material

such as brass or stainless steel, and constructed in such a manner as to be permanently rigid. Pans

and covers shall be made so as to nest with the sieves. The wire cloth shall be mounted on the frame

Without distortion, looseness, waviness. To prevent the material being sieved from catching in the

Joint between the wire cloth and the frame, the joint on Sieves #25 and smaller opening shall be

filled smoothly with solder or made so that the material will not be trapped.

4.2 Standard Franmes: The standard sieve frame shall be circular, 203.2 mm (8.0 in.) in diameter, of

seamless construction. The permissible variation on the mean inside diameter at 5.08 mm (0.2 in.)

below the top of the frame shall be +0.762 mm (0.03 in.). The bottom of the frame or "sieve skirt"

shall be constructed so as to provide for an easy sliding fit in any sieve conforming to the above

permissible variation, and in no case shall this outside diameter be less than 202.438 mm (7.970 in.)

nor more than 203.20 mm (8.000 in.). The height of the sieve from the top of the frame to the wire

cloth surface shal1 be either 50.8 mm (2.0 in.) designated as full-height, or 25.4 mm (1 in.),

designated as half-height. The joint or fillet shall be constructed to provide a minimum clear sieving

surface 190.5 mm (7.5 in.) in diameter.

4.3 Non-standard Frames: Frames of sieves having nominal openings of Iess than 25 mm (1 in.), but

greater than 4.00 mm (0.157 in.) may be either of the standard size or of larger dimensions as may be

specified in individual cases. Frames of sieves having nominal openings of 25 mm (1 in.) or more

may be larger than the standard size. The use of special size and shape frames for special purposes is

not precluded. For some purposes, sieve frames larger than the standard size may be either square,

Rectangular, or circular, and for nominal openings of 25 mm (1 in.) and coarser may be made of

metal or hardwood. The use of special size and shape frames, however, shall be discouraged where

the standard frames may be used, because the results are not necessarily comparable.

4.4 3 in (76.2 mm) Sieves: The tolerances on the diameter of the sieve frames shall be the same as for

the standard size. The depth of the sieve from the top of the frame to the cloth shall be normally

31.75 mm (1.25 in.), but not less than 19.05 mm (0.75 in.).

5. Product Marking:

Each sieve shall bear a label marked with the following information.

- This ASTM designation, No (ASTM E 11)

- Standard sieve designation (from Table Column 1)

- Name of manufacturer or distributor.