Wire, strip, ribbon, foil and formed elements — sizes, tolerances and packing.
| Form | Size range | Typical | Supply / packing |
|---|---|---|---|
| Round wire | φ 0.03 - 10 mm | φ 0.5 - 6 mm most common | Spool, coil or straight lengths; spiral winding available |
| Flat strip / ribbon | Thickness 0.05 - 3.5 mm | Width 2 - 300 mm | Slit to width; single or multiple widths per coil |
| Foil | Thickness 0.02 - 0.1 mm | Narrow width | Precision resistance and sensing applications |
| Formed elements | Corrugated / edge-folded | To drawing | Strip formed for rigidity and larger surface area |
| Radiant tubes | Tube OD and wall per drawing | 310S / 2520 sheath | Inner element + sheath + terminals, assembled |
| Heat-resistant parts | Tray / rail / retort / tube | 310S / 2520 / 1Cr18Ni9Ti | Machined or fabricated to drawing |
| Item | Tolerance |
|---|---|
| Wire diameter | Per agreed standard; typically ± 0.02 mm on fine sizes |
| Strip thickness | Per agreed standard; thickness controls resistance |
| Strip width | Slit to width with agreed tolerance |
| Length / weight | Coil weight or cut lengths to order |
| Straightness | Per product form; wire and rod supplied in coils or straight lengths |
Tolerances are agreed per order and confirmed in the order acknowledgement. Thickness and diameter control the electrical resistance — please specify the tolerance critical to your process.
| Quantity | Formula |
|---|---|
| Resistance (strip) | R = ρ × L / (width × thickness) |
| Sheet resistance | Rs = ρ / thickness (per square) |
| Resistance (round wire) | R = ρ × L / (π × (d/2)²) |
| Surface load | P / developed surface area (W/cm²) |
From φ 0.03 mm up to 10 mm; φ 0.5-6 mm covers most furnace element applications. Spiral winding is available to drawing.
Thickness 0.05-3.5 mm and width 2-300 mm. Strip can be slit to width and supplied as corrugated or edge-folded formed elements.
Resistance R = resistivity × length / (width × thickness). Sheet resistance equals resistivity divided by thickness, so changing thickness requires recalculating length.
