Absolute Micron Retention/Absolute Micron Rating
In Dutch Weaves, because the wires are woven tightly together, the aperture size cannot be calculated in the normal manner. There are two methods by which the aperture size can be determined, bubble point testing and glass bead testing – the absolute micron rating determines the maximum particle size (spherical) that can pass through the mesh. (see also nominal micron rating)

Annealing
A heat-treating process in which metal is heated to some elevated temperature, held at this temperature for a period of time, and then cooled

Annealed after Weaving
Wirecloth which is annealed after the weaving process – this allows mesh to be more easily shaped or pressed into complex forms

Annealed Wire
Wire which has been cold-drawn to reduce its diameter is annealed to soften the wire and increase the elongation to facilitate weaving

ANSI
Abbreviation for the American National Standards Institute

Aperture
The clear opening between wires

ASTM
Abbreviation for the American Society for Testing and Materials

Backing Cloth, Backing Mesh
Wire mesh or wirecloth which is utilised to provide support for a screen surface

BMT
Abbreviation for Broad Mesh Twill Dutch Weave – in this style of weave, the weft wires are regularly spaced rather than packed in tightly for better surface filtration and improved accuracy of the opening

Bolting Cloth 
A group of industrial wirecloth specifications in which the wire diameter is lighter than standard commercial
grades producing a more open cloth for increased rates of filtration

Broad Mesh Twill – see BMT

Bubble point test
In a test to determine the micron rating of Dutch Weaves, the pressure required to pass air bubbles through the mesh  (covered by a test liquid) is measured. The average aperture size is then calculated by taking into account surface tension, liquid density, temperature and immersion depth (see absolute micron retention) (see glass bead test)

Calendering, Calendered wirecloth
Wirecloth is passed through a set of heavy rollers to reduce the thickness of the cloth to achieve a desired thickness (caliper), or to flatten the wires at the knuckle (crimp) providing a smooth surface, or to lock the weave

Clear Opening
The space (aperture) between adjacent parallel wires – an alternative way of specifying a mesh size

Commercial Quality
wirecloth produced for general industrial applications, as opposed to Test Sieve Quality

Crimp
The indentation that is formed in the wire during (or prior to) the weaving process, providing a locking arrangement for the warp and weft wires

DIN
Abbreviation for the German Institute for Standardisation

Drawing
Reducing the cross section of wire by pulling it through a die

DTW
Abbreviation for “Dutch Twilled Weave”

Ductility
The ability of a material to deform plastically without fracturing, being measured by elongation or reduction of area in a tensile test, or by other means

Dutch Weave
Wire mesh or filter cloth with warp wires larger than the weft wires. Warp wires are regularly spaced and remain straight while adjacent weft wires are woven tightly together, resulting in a dense, strong material

Elongation
Expressed as a percentage, elongation is the amount wire will stretch before breaking

Ferrous alloys
Alloys or metals containing iron

Fill, Fill Wires
Weft, weft wires

Filter
A device using filter media for particle retention, for the clarification of a liquid or gas etc

Filter Cake
Solids retained on the filter surface during the filtration process

Filter cloth
A generic term for wirecloth produced in any type of Dutch Weave

Filtration
The process of clarifying a fluid or gas etc. by the removal (retention) of solid particles

Galvanise
To coat iron or steel with zinc, primarily to prevent rust

Gauge
A term referring to the size (thickness) of wire diameter

Glass Bead Test
Precision measured glass beads are passed through a Dutch Weave mesh – the diameter of the largest bead passing through is considered as the absolute micron retention (see absolute micron retention) (see bubble point test)

Herringbone Twill
In which the direction of a twilled weave is reversed at regular intervals to stabilise the mesh structure, identified by a visual chevron or herringbone effect in the cloth

Hi-Flo
A Plain Dutch Weave in which the weft is thinner than usual producing a higher flow rate

Hollander Weave
As Dutch weave

HP
An abbreviation, for Plain Dutch Weave (Hollander Plain) – a mesh designated as HP 120 will have a nominal micron rating of 120 (0.120mm)

HT
An abbreviation, for Twill Dutch Weave (Hollander Twill) – a mesh designated as HT 15 will have a nominal micron rating of 15 (0.015mm)

Intermediate Crimp
Mesh with extra crimps in the warp and/or weft wires between the wire intersections – the wire is shaped prior to weaving

ISO
The International Organisation for Standardisation

ISO 4782 standard governs metal wire for industrial wire screens and woven wirecloth

ISO 9044 standard governs industrial wirecloth

Knock-up
The weft, or weft mesh count

KPZ
An abbreviation for Reverse Dutch Twill Weave

Market Grade
A group of industrial wirecloth specifications suitable for general purpose screening applications

Mechanical Properties
Generally refers to physical characteristics of the wire (elongation, tensile strength etc.), but can also refer to the tensile strength of the woven material (the latter requiring specialised testing equipment)

Mesh Count
This generally denotes the number of apertures in a length of 25.4mm (1″) – this is the most widely used way of specifying wirecloth. Other methods include mesh per cm, aperture size (mm or micron) etc

Micron
One thousandth of a millimetre, 1 micron = 0.001mm

Multi-Ply (Multi-Plex)
Of a weave, when the wire strand (usually the warp) is made up of more than one wire, either twisted together or lying side by side

Non-Ferrous
Metals or Alloys containing no iron, such as copper, brass, aluminium, etc

Nominal Micron Rating
For Dutch Weaves, the nominal micron rating is a guide to the smallest particle size retained by the wirecloth in general usage  (see also absolute micron rating)

Open Area
The ratio of the free area between the wires to the total area of a given section of wirecloth, expressed as a percentage

Opening
As aperture, the measured space between two adjacent (parallel) wires

Particle Retention
The particle size that will be retained by a given mesh, usually expressed in microns

Physical Properties
The properties of metal, other than mechanical properties, that pertain to the physics of a material – for example, density, electrical conductivity, heat conductivity, thermal expansion etc

Pitch
The distance between the centres of two adjacent parallel wires

Plain Weave
Woven wirecloth in which each warp and each weft wire passes over one and under the next adjacent wire in both directions

Porosity
The fractional void volume of the mesh

PZ
An abbreviation for Reverse Plain Dutch Weave, for example PZ 80 which will have a nominal micron rating of 80

Raw Edge
Denoting the edge of a panel or roll of wirecloth which has been cut and does not have any special finish or treatment to the edge

Rectangular Mesh
Wirecloth having a different mesh count in the warp and weft direction, producing a rectangular opening – usually, the weft count is reduced, and the weft wire may be heavier than the warp to stabilise the weave. A rectangular mesh can provide a greater screening (open) area with the same micron rating as a corresponding square mesh depending on the nature of the material being filtered

RPD
Abbreviation for Reverse Plain Dutch Weave (see also PZ)

Seam
A method of joining two pieces of wirecloth to form a single larger piece

Selvage (selvedge)
The edge or border of wirecloth finished off so as to prevent unravelling, traditionally the looped edge finish produced when weaving on a shuttle loom

Shoot or Shute
Weft, or weft wires

Space Cloth
Square coarse mesh wirecloth which is designated by the width of the open space between the inside edges of two parallel wires

SPW
Abbreviation for Single Plain Dutch Weave

Square Mesh
Wirecloth with the mesh count and wire diameter the same in both directions

Stroke Back Edge
A finished edge in which wires are brushed back to form a dense layer to lock in the edge warp wire

SWG
An abbreviation for Standard Wire Gauge, an obsolete designation for wire diameter

Tensile Bolting Cloth
Often abbreviated as TBC, see Bolting Cloth

Tensile Strength (UTS)
The maximum stress that a material can with stand while being stretched or pulled before failing or breaking

Test Sieve Quality
wirecloth produced in small quantities under stringent conditions to produce exact and certifiable apertures

TRD
An abbreviation for Twill Reverse Dutch Weave

Twill Weave
Woven wirecloth in which each weft wire passes successively over two and under two warp wires and vice versa

Warp
The wires in the longitudinal direction of the weave, can refer to a single wire or all the warp wires together

Warp Beam
Where warp wires are prepared and held prior to and during the weaving process

Web
A single weaving batch

Weft
The wires that run across the width of the cloth (also shoot, shute, woof)

Wirecloth
A general term for material woven from metallic wires

Yield Strength
The stress at which a material is transformed from an elastic, to an inelastic (plastic) state