Stainless steel wire cloth (see below), used in filtration and straining.  It is typically 36 x 36 or 36 x 32 mesh, and is woven in any desired metal.  The warp is formed by 36 groups of wires per inch, each group including 5 wires .007” diameter lying side by side and woven as one, while the shute will consist of 36 or 32 groups per inch, each with 7 wires with a diameter of .005.

BACK-UP CLOTH – A heavy wire mesh, usually calendered, supporting a finer mesh in filtration or straining.
BOLTING CLOTH – A variety of square-mesh Standard wire cloth, described below under “Mesh, Square.”
BUNCHED WIRE – See “Mesh, Stranded” below.

CALENDER – To pass wire cloth between heavy rollers.  This flattens the high points at the intersections of the wires and gives the material a smoother surface.  Heavy wire cloth, when used as a support for a lighter, fine-mesh material (“back-up cloth”), is usually calendered to reduce wear on the more delicate cloth.  Calendering can also give a finer degree of filtration with a particular mesh and wire diameter.  Also called “Rolling.”

CLEAR OPENING – See “Opening” below.

COIN – To stamp wire cloth for the purpose of shaping or compacting it.  Wire-mesh discs are often coined at the edges to lock the wires together and reduce raveling.

COUNT – The number of openings per lineal inch in a woven material; also called Mesh.

CRIMP – Corrugations in the wires of woven-wire cloth, which tend to hold the wires in place and reduce the deformation of, hole size and shape in use.  In the lighter meshes, crimps at the points of intersection are formed automatically by the action of the loom; in the heavier meshes the wires must be crimped before weaving.  As opening size and wire diameter increase, crimping by the loom becomes less pronounced and, at the same time, more necessary if the cloth is to be stable.  Hence pre-crimping is required with the heavier wires and more open weaves.  Boegger can pre-crimp in one direction.
Crimp, Double – Crimps in both warp and shute at all points of intersection, formed automatically by the loom.  Plain-weave square mesh wire cloth is also called “Double-Crimp.”

Crimp, Flat-Top – Lock-Crimp wire cloth with all crimps on the lower surface only, to leave the top surface smooth and all in one plane.

Crimp, Inter or Intermediate – Extra crimps, formed in the wires before weaving, in either or both warp and shute and spaced equally between the normal crimps at the points of intersection.  It is used mostly in the coarser weaves of light wire.  Also called “Multiple Crimp.”
 
Crimp Lock – Similar to Intermediate Crimp, except that the additional crimps are close to both sides of every point of intersection instead of half-way between.  It gives maximum rigidity and firmness to the cloth, and helps maintain even spacing of the wires in the very open weaves.
 
Crimp, Multiple – See “Crimp, Intermediate” above.

Crimp, Semi-Intermediate – Intermediate crimping in the shute only.  In addition to the normal double crimp in both warp and shute.

Crimp, Single – Crimps in warp only, or shute only, at the points of intersection.

DOUBLE WIRE CLOTH – One of the two major types of wire cloth (the other is Standard).  It has warp wires heavier than the shute, and the shute is driven up tight so that the wires overlap to form narrow, twisting passageways through the cloth that appear triangular when the material is viewed diagonally.  You cannot see directly through Dutch, as you can through Standard, wire cloth.  The weave may be plain or twilled (see illustrations under “Weave” below), and both varieties offer greater rigidity and 4 to 8 times the mechanical strength of Standard wire cloth for equal particle-retention.  Its principal use is in straining and filtration.  Compare with “Standard Wire Cloth” below, and see also the Catalog sections on “Filter Cloth” and Strainers.”

FEDERAL SPECIFICATIONS – Wire Cloth.  The following apply to many non-MIL applications:
 Industrial Wire Cloth – RR-W-360
 Insect Wire Screening – RR-S-141a

FILL, FILLER, FILLING – See “Shute” below.

FILTER – A device employing filter leaves or tubes of woven-wire cloth, often with an additional filter medium such as a pre-coat of diatomaceous earth.  They are used for the clarification of a liquid or gaseous fluid or the precision removal of particles known to be present.  Compare with “Strainer” below; see the sections on “Filter Cloth,” “Off-Count Mesh,” and “Strainers.”

FILTER CLOTH – Wire Cloth used for filtration and straining.  It includes primarily plain and twilled Dutch wire cloth, and also certain specifications of square-mesh and off-count Standard wire cloth.  It is used for filter elements, and is fabricated by Boegger into strainers and other mesh products.  Full information is in the “Filter Cloth” section.

FILTRATION – The clarification of a fluid by the removal of solid particles.  See also “Retention,” and compare with “Straining” below.

GAGE, GAUGE – The measure of a wire diameter, expressed as an arbitrary number in accordance with one of several different gage systems such as American Wire Gage, Washburn & Moen, etc.  To avoid confusion, wire sizes should always be given in decimal fractions of an inch – but when a gage designation is used, the system must be identified.

HARDWARE CLOTH – An inexpensive grade of square-mesh, plain-weave Standard wire cloth, galvanized-after-weaving, and made of a relatively light wire.  The mesh is generally between two and eight (openings per lineal inch).

MARKET GRADE – A variety of Standard wire cloth, described below under “Mesh, Off-Count.”

MESH – The number of openings per lineal inch in a woven materials; also called Count.

MESH, OBLONG OR OBLONG-SLOT – See “Mesh, Rectangular” below.

MESH, OFF-COUNT – Standard wire cloth, plain or twilled weave, with the shute spaced more widely than the warp by 5% or more.  It has a greater percentage of open area and flow rate than the equivalent square-mesh cloth, and is more economical for a given application.  In specifying off-count mesh, the number of openings per inch (“mesh”) counting across the warp wires is given first, then the mesh counting across the shute. The major varieties of Off-Count Mesh are as follows:

Market Grade – An economical straining material in any desired metal, woven in meshes from 40 x 33 in .012” diameter wire to 200 x 190 in .0021” diameter wire.  It is stronger than the equivalent Strainer Cloth.

Pressing Cloth – A copper, nickel or Monei material used in the head and buck of commercial pressing machines to distribute the heat evenly.  Meshes are 50 x 40, 60 x 50, and 64 x 56 only, in wire diameters from .0065” to .009”.

Strainer Cloth – The least expensive fine-mesh wire cloth made, woven in brass only.  Originally developed for dairy industry, it now has many household and light industrial uses such as straining paint and liquid fuel.  It is sold in 100-foot lengths, and is also packaged in rolls of five square feet for sale through hardware stores.  Most specifications of Strainer Cloth are off-count, ranging from 40 x 32 in .0075” diameter brass wire to 120 x 88 in .0035” diameter brass.  In addition, two brass square mesh material are classified as Strainer Cloth: 20 x 20 and 30 x 30 mesh, in .01” and .007” diameter wire respectively.  In comparison with Market Grade, the wires in Strainer Cloth are slightly thinner and the mesh is slightly more open.

MESH RECTANGULAR – Plain weave Standard wire cloth with rectangular or oblong openings.

MESH, STRANDED – Wire cloth with both warp and shute composed of several wires lying side by side and woven as one.  Stranded wires are also called “Bunched.”

MESH, SQUARE – Plain or twilled Standard wire cloth, with equal spacing of warp and shute to give square openings.  In meshes of 2 per inch and finer it is specified by the number of openings per lineal inch; in meshes coarser than 2, by the center-to-center distance between adjacent parallel wires. Two minor varieties of Square-Mesh cloth are:

Bolting Cloth – A precision-woven square-mesh Standard wire cloth, woven on special double-stroke looms, of custom-drawn wire (usually Type 304 Stainless) with a super-smooth finish.  It has the maximum possible uniformity of hole size, with lighter wires and a greater percentage of open area than similar specifications of regular square-mesh cloth.  Bolting Cloth is used for sifting and sizing fine powders such as flour and ceramics, for removing fine particles from slurry, and in preference to silk in screen-printing processes.

Space Cloth – Plain-weave square-mesh Standard wire cloth with opening slightly larger than the equivalent ordinary square mesh material.  Since it is used for the sizing of coarse dry solids such as coal and gravel, the basis of specification is the width of its clear opening – the distance between the inside surfaces of adjacent parallel wires.  Openings range from 1/8” x 1/8” to 4” x 4”.

MICRON – 1/1000 millimeter; 0.00003937 inch; represented by the Greek letter mu.  It is the unit of measurement of the particle-retention of filter media.  A table of micron/inch equivalents is given in the Conversion-Table section.

MICRON FILTER CLOTH – Dutch wire cloth in meshes giving a particle retention of, roughly 50 microns or finer.

OPEN AREA – The ratio of the area of the open spaces between the wires to the total area of a piece of wire cloth, expressed as a percentage.  The formula for computing this value is given on Page 9.

OPENING – The distance between the inside surfaces of adjacent parallel wires.  It is the basis of specification of Space Cloth, and a controlling factor in the retention of wire cloth.

PRESSING CLOTH – A variety of Off-Count mesh; see above.

RECTANGULAR MESH – See “Mesh, Rectangular.”

RETENTION, RETENTIVITY – The ability of a filter medium, such as wire cloth, to prevent the passage of solids.  It is expressed in terms of the diameter, usually in microns, of the largest spherical solid particle that will normally pass through the filter material.

RIDDLE, FOUNDRY – A type of coarse-mesh sieve for separating or sizing relatively large objects or particles.  They usually have wooden rims, range from 12 to 14 inches in diameter, and employ wire cloth from 2 to 8 mesh.

ROLL – The normal unit of bulk sale of wire cloth.  The nominal length is 100 feet, +/- 10%.  Widths range from 24” up, with tolerances of 1/16” to ¼” according to mesh.  Invoices are based on the actual length supplied.

SELVAGE – (“self-edged”).  A finished edge on wire cloth to prevent raveling.  The traditional selvage is woven into the edges of rolls 24” and more in width, and cannot be added after weaving.

SELVEDGE – A Boegger-patented method of salvaging the edges of wire cloth after it has been woven and cut into strips from 1 to 8 ¼” wide.   It can be applied only to the opposite long sides of such strips, parallel with the warp wires.

SHIELDING CLOTH – Wire cloth used for shielding radio-frequency equipment and rooms.  Per MIL-E-4975A (ASG).  It is 22-mesh with .015” diameter unlacquered copper wire.  The warp is soft-annealed, the shute hard-drawn.

SHOOT – See “Shute” below.

SHUTE – The wires running crosswise in the cloth as woven.  They are passed back & forth through the warp wires by the shuttle in the loom.  Corresponds to the “Weft” or “Woof” in textiles, and is also called “fill.”  See the illustration under “Weaves.”

SPACE – The clear opening between the wires in woven-wire cloth.

SPACE CLOTH -  A variety of plain-weave square-mesh Standard wire cloth, described above under “Mesh, Square.”

STANDARD WIRE CLOTH – One of the two major types of wire cloth (the other is Dutch). It has warp and shute wires of equal diameter, is woven plain and twilled in square and off-count meshes.  Its holes lies in the plane of the cloth so that you can see straight through, as contrasted with Dutch wire cloth (see above).

STRAINER – An assembly of woven-wire cloth for the removal of unwanted foreign particles from a stream of liquid or gas.  It includes any necessary fittings and reinforcements, is usually complete in itself, and may be considered as a protective device primarily.  Contrast with “filter” above, and see also the sections on “Filter Cloth,” “Off-Count Mesh,” and “Strainers.”

STRAINER CLOTH – A variety of Standard wire cloth; see under “Mesh, Off-count,” above.

STANDARD WIRE CLOTH – See “Mesh, Stranded” above.
 
TWILLED – See under “Weave” below.
 
WARP – The foundation wires of woven-wire cloth, formed of wires running the long way of the material as woven.  The warp wires are alternately raised and lowered during weaving, and the shute wire is passed back & forth between them in the shuttle.  The weave – plain or twilled – is determined by the heddle pattern of raising and lowering the warp wires.  See illustration under “Weave.”
 
WEAVE – The pattern of interlaced warp and shute wires in woven-wire cloth, determined by the sequence in which individual warp wires are raised and lowered by the heddle for passage of the shuttle carrying the shute wire.

Weave, Double-Crimp – A designation of the finer meshes of plain-weave square-mesh Standard wire cloth that take a double crimp automatically in the loom.  See “Crimp” above.

Weave, Herringbone-Twill – Twilled wire cloth with the twilling reversed at regular intervals to produce a multiple-V or herringbone pattern.

Weave, Plain – Each shute wire passes alternately under and over successive warp wires, and each warp wire passes alternately over and under successive shute wires.  Used in Standard and Dutch wire cloth.

Weave, Plain-Dutch – Dutch wire cloth (warp wires heavier than shute) in plain weave.
 
Weave, Twilled – Each shute wire passes alternately under and over two successive warp wires and each warp wire over and under two successive shute wires, in a staggered arrangement creating a diagonal pattern in the cloth.  Twilling requires less bending of the wires than plain weave, allowing heavier wire for a given mesh to provide greater strength.  Both Standard and Dutch cloth are twilled.

Weave, Twilled-Dutch – Dutch wire cloth (warp wires heavier than shute) in twilled weave.

WEFT - See “Shute” above.
 
WIRE CLOTH – A general term for material woven from metallic wire.

WOOF – See “Shute” above.