Forms

Sheet

Sheet is defined as a material in a thin, flat form. Extremely thin sheet is classified as foil (see Foil definition below) and sheet 6mm and thicker is classified as plate.

Advent’s sheet thicknesses range from 0.25mm – 5.0mm

Foil

A foil is a very thin sheet of material, which will bend under its own weight. For the purpose of Advent’s catalogue if the material can easily be wound into a coil, it has been defined as a foil. This upper thickness limit varies depending on the material, but is specified for each material in the online catalogue. For most materials in stock, a foil’s upper thickness limit is around 1mm.

Advent’s foil thicknesses range from 0.000025mm – 1.0mm

Plate

Plate is defined as thick sheet which is 6mm or greater.

Wire

Wire is defined as a single cylindrical piece of material that will bend under its own weight. It can be also be easily wound or manipulated.

Advent’s wire diameters range from 0.005mm – 5.0mm

Wire – Straight cut lengths

This is defined as a wire that has been mechanically straightened.

Rod

A rod is a solid cylindrical piece that is straight and will not deform under its own weight.

Advent’s rod diameters range from 2.0mm – 80mm

Mesh

This consists of woven strands of metal wire. The mesh is defined by the number of wires per inch in the vertical and horizontal axis. For example 100 mesh per inch indicates that there are 100 wires per inch both vertically and horizontally. 40 x 32 mesh per inch indicate that there are 40 wires per inch in one direction, and 32 wires per inch in the other orientation.

Surface finish

Condition oiled

This term indicates that the surface of the material has been covered with an oil based layer to prevent degradation of the surface (oxidation or corrosion).

Condition degreased – clean

This term indicates that the surface is ‘clean’ and any surface oils have been removed.

De-scaled

This term indicates that the surface oxide has been removed.

Pickled Finish

This process chemically removes oxides and scale from the surface of the metal by the action of water solutions of inorganic acids.

Condition ground

This term typically applies to rods and indicates that the material has been ground to reach its final diameter.

Machined

This indicates that the material has been machined to produce the final dimensions.

Smooth forge clean

This terminology is used in reference to rod material and indicates that the rod diameter has been achieved through an intricate forging process. This produces tight tolerances without the need for machining.

Polymer specifications

Quadruple Teflon (PTFE)

Formvar

Polyimide insulated

Condition type HN

Condition Type C Film

Material analysis

Typical Analysis

When ‘Typical Analysis’ is listed for a catalogue item, all figures will be in parts per million (ppm) unless otherwise stated. This data is a typical analysis for that item; however there is no guarantee that the material shipped will conform to the data listed. In many cases the values stated for a specific element will be a maximum value.

Actual Analysis

When ‘Actual Analysis’ is listed for a catalogue item, as with the ‘Typical Analysis’, all figures will be in parts per million (ppm) unless otherwise stated. The data will be specific to the current batch in stock for that item.

The purity listed refers to the Total Metallic Impurities (TMI). This excludes non-metallic impurities, unless otherwise stated.

Tempers

Temper annealed

This heat treatment involves heating the material to and holding it at a suitable temperature, before cooling the material at a controlled rate, slow enough to allow the removal of internal stress, crystal defects and dislocations. When the annealed part is allowed to fully cool down under these controlled conditions it is defined as a ‘full annealing’ and produces a relatively soft, ductile end product.

Temper ‘Stress Relieved’ annealed

When a metal is plastically deformed by methods such as rolling, hammering or drawing at room temperature, this produces a ‘work hardening’ effect (an increase in the material hardness and reduction in ductility). ‘Stress relieving’ is a low temperature annealing heat treatment for removing internal stresses, produced by work hardening.

Temper hard

This definition indicates that the material has undergone a hardening process resulting in a direct increase in hardness. The five main hardening mechanisms are hall –petch hardeneing, cold working, solid solution strengthening, precipitation hardening, martensitic transformations and case hardening. With the exception of martensitic transformations, all hardening processed are achieved by the introduction of dislocations or defects into the crystal lattice, acting as a barrier to slip, therefore increasing the hardness of the material. The precise hardening mechanism is not defined for our catalogue items.

Temper half hard & quarter hard

The term ‘temper half hard’ and ‘temper quarter hard’ indicates that the material has undergone a hardening process resulting in an increase in hardness that is proportionally less than what is achievable in a fully hardened state for that specific material.

Temper hot rolled

This is the plastic deformation / rolling of metal at a temperature sufficiently high enough to avoid the ‘work hardening’ effect. The lower limit of temperature for this process is the recrystallization temperature of the material being deformed.

Temper as rolled

The phrase ‘temper as rolled’ is a generic term used within the catalogue to refer to material that has not been subject to a specific heat treatment or hardening process after the manufacturing process has been completed.

Temper as drawn

This is a terminology specific to wires and indicates that the diameter of the wire has been reduced by pulling it through a single, or series of, drawing die(s). This process is typically carried out at room temperature, and is therefore usually a cold working process. However, for large diameter wire it is sometimes carried out at elevated temperature to reduce forces. The extensive cold working that is undergone by the wire during drawing can result in a substantial increase in the wires tensile strength.

Temper as extruded

This term is used in reference to the extrusion of wire. This process is similar to drawing wire with one subtle difference. The final wire diameter is produced by >pushing it through a single, or series of, die(s).

Manufacturing processes

Condition Electron deposited

This term indicates that the material has been produced by the deposition of the metal on a cathode during electrolysis.

Sintered

Sintering is a process of converting powder into a continuous / solid mass. In this process particles of powder are fused together by a combination of pressure and heat at a temperature below the melting point of the material.

Vacuum melted

Water atomized

Water Jet Cut (WJC)

This term indicates that the material has been cut using a water jet.

Thin film specifications

Pinhole Free / Light Tight (LT)

In general, foils thicker than 0.025mm will be free from pin holes / light tight. However at thicknesses of less than 0.025mm some pinholes may be present. Where a foil with a thickness less than 0.025mm has been specified as light tight, this means that no pinholes can be seen at x2 magnification.

For foils less than 0.025mm, which are not specified as light tight, we can attempt to especially select pinhole free material, at an extra cost. It must be noted that some of the thinnest foils pinhole free material is not available.

Not Light Tight (NLT)

If the material is specified as not light tight pin holes can be seen in the material at a magnification of x2.

Vacuum Tight (VT)

Vacuum Tight is defined as no detectable leakage when checked on a helium mass spectrometer with a sensitivity of 10–8 atm cm3S–1. In Advent’s foil range, currently only Beryllium foils are available Vacuum Tight (VT).

Support Permanent Mylar

The mylar film is used as a supportive layer onto which a extremely thin metal layer is applied to >one side only.